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There are few names more synonymous with high-performance vehicles and racing than Holley. A Holley carburetor is a great way to ensure that your high-performance classic car gets the best air-fuel mixture possible and that you can tune it to suit your specific needs. There are several different Holley carb models, and they all have their own specs and strengths. Knowing how to identify a Holley carburetor will help you get the right one for your vehicle and your performance goals.
Understanding Holley Carburetor Models
Holley carburetors come in a variety of models and designs. Each one is built to provide different performance specs and tunability. If you come across a vehicle with a Holley carb that has the feel and power you are looking for, it can be helpful to know how to ID Holley carb types so you can get the right one.
- Holley 4150. The Holley 4150 is the classic version of the Holley carb and features a square bore flange. This version is highly customizable with different jets and floats, making it a great choice for those who love mods.
- Holley 4160. The 4160 model is similar to the 4150 but it has a vacuum-secondary system and has a horizontal fuel transfer tube on the throttle lever side. This version is more street-friendly and is known for improving acceleration and overall drivability.
- Holley Dominator. The Dominator is one of Holley’s high-performance models. It has a large-bore design that injects a lot of air and fuel into the combustion chamber. It is physically larger in both size and intake mounting bolt pattern.
- Holley Street Avenger. Holley’s Street Avenger model has a modular setup that makes it incredibly easy to customize. This makes it a great option for street performance and fine-tuning.
- Holley Ultra XP. The Ultra XP Model is specifically designed for racing. The adjustable fuel bowls and billet finish make it perfect for incredibly high-horsepower engines.
Visual Clues For Identification
When learning how to identify a Holley carburetor, it can be helpful to know what visual clues to look for. This way, if you are at a car show or a race, you can seek out the vehicles with the specs you are looking for and find out what kind of carb they are using. While many Holley carbs look similar, there are some distinct characteristics you can look for that will help you ID them.
Shape And Size
The shape and size of a Holley carb will be a dead giveaway as to the type. The 4150 and 4160 models have a rectangular shape and a four-barrel design. If you want to be able to tell the difference between these two models, look at the secondary system. The 4150 has a mechanical secondary while the 4160 has a vacuum secondary. The vacuum system will be located on the left side of the carb and look like a large metal cap facing upwards. The Holley Dominator will be much larger than the 4150 and 4160, making it easy to identify.
Throttle Body Design
One of the best ways to do a Holley carburetor identification is to look at the throttle body. The throttle body on a 4150 or 4160 Holley carb is small and square. The Dominator and other high-performance carbs have a much larger throttle body that is also angular instead of symmetrical like it is on the standard carbs.
Material And Finish
If you want to know how to identify a Holley carburetor, most of the time you can simply look at the finish. Many of the standard carbs like the 4150 and 4160 have a die-cast aluminum construction and either have a polished finish or chrome. The more high-performance and racing-oriented models like Dominator and Ultra XP usually have a billet finish that is more matte in appearance.
Model Number Stamp
In some cases, you can do a Holley carburetor identification by looking at the carb itself and reading the model number stamp. Many Holley carbs have the model number stamped on the choke horn if the carburetor has a choke. Some of the more high-end versions will even have a stamped tag attached to the carburetor body. This makes it easy to identify. However, not all models have this stamp and some owners will remove the tag if they think it gets in the way of the look of their vehicle’s engine, so it is best to know how to ID a Holley carb without the model number.
Which Holley Carburetor Is Right For Your Vehicle?
While learning how to identify a Holley carburetor is important, choosing the right one for your vehicle is just as crucial. The type of carb that will be right for your needs will depend on what your priorities are and the kind of vehicle you have. Knowing what factors to consider will help you make the right choice. Some of the things you should consider include:
- Vehicle application. Knowing what you usually use your vehicle for is a great way to find out what kind of Holley carb you need. If you want a carburetor for everyday driving, a 4150 or 4160 model will be sufficient. If you are looking for racing applications, though, a higher-end version such as a Dominator could be your best bet.
- Engine size. For small to medium-sized engines, a 4160 or Street Avenger will be your best bet due to their smooth acceleration and reliability. For large engines, the Dominator’s enhanced airflow will give you the best possible performance.
- Performance preferences. If you are going to choose the right carburetor, you need to know what your performance goals are. If you are looking to increase performance, the tunability of the 4150 or the high airflow of the Dominator makes them great choices.
If you want the best Holley carburetor for your vehicle’s needs, JEGS is your source. Our large selection of Holley components and carbs lets you pick the perfect model for your performance goals and your specific car. Complete your order online to get your new carb delivered right to your shop.
38 responses to “How To Identify A Holley Carburetor”
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I have a Holley Four-Barrel
List # 80457
Date Code # 1714I know from the Holley website that it is in the 4160 group
My question how do I find the R-number on the Holley Card and what the CFM is for the carb ( 600,650etc..)
This came off of 1968 GT Coupe 289-
Danny, the list number 80457 tells you most of what you are looking for. That carb is part of the Holley 4160 series and it is a 600 cfm vacuum secondary carb with an electric choke, which is one of Holley’s most common street performance setups. The date code 1714 just tells you when it was manufactured and does not affect the specs. On Holley carbs, the “R” number is essentially the list number itself, so your 80457 is the reference number you use when looking up specs or parts. You will not typically find a separate R number stamped elsewhere on that carb. Since you already have the list number, that is the correct identifier for rebuild kits, tuning parts, and general information. As for it being on a 1968 Mustang 289, that carb would not be original to the car, since it is a later replacement style carb, but it is a very good match for a small block Ford and works well for street use. If you would like help dialing it in for your setup or confirming any details, give us a call at 1-800-345-4545 and speak with a Tech Specialist and we will be glad to help.
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Charlie, the 76750-0 number is a Holley list number, and that identifies your carb as part of the Holley 4160 series. That series is a 4 barrel, square bore design that uses vacuum secondaries, which makes it a very popular choice for street driven applications because it delivers smooth operation and good drivability. The 76750 family is commonly a 600 cfm carb with an electric choke, so it is very similar in function to other street performance Holley carbs but with the 4160 style metering setup on the secondary side. The 2053 number you see is a production or date code and does not change the core identification of the carb itself. If you are looking for parts or tuning components, you will want to reference the Holley 4160 series for proper fitment. If you would like help dialing in the carb or making sure it is matched well to your engine, give us a call at 1-800-345-4545 and speak with a Tech Specialist and we will be glad to help.
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I’m trying to identify a carb I have had for a while. The number on it is:
3886091-AN
LIST-3418-1
833
I can’t locate any literature telling me what I have.Thanks.
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Al, that carb is an original Holley OEM unit built for GM, not an aftermarket performance carb, which is why it can be tough to find info using modern Holley catalogs. The 3886091-AN casting number is a GM part number, and LIST 3418-1 identifies it as a Holley 4150 style square bore carburetor that was factory installed on late 1960s Chevrolet big block applications. This carb is generally recognized as a vacuum secondary unit in the roughly 600 CFM range, not a 750. The “833” stamping is the Holley date code, which decodes to the 33rd week of 1968, lining up perfectly with those GM big block applications. These carbs were commonly used on 396 engines and some 427 combinations that prioritized drivability over outright airflow. Because it is an OEM Holley, service parts like gaskets and rebuild components are still available, but they are usually matched by carb family and fuel bowl style rather than by an exact modern part number. If you want help confirming rebuild components, throttle bore sizes, or compatibility with your current engine setup, give us a call at 1-800-345-4545 and one of our tech specialists will be happy to walk through it with you and make sure you get the right parts.
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Johnny, the number 80457-10 is a Holley list number, and that identifies your carb as part of the Holley 4150 series. That specific series is a 4 barrel, square bore design that is very commonly used on street performance small block and big block setups. The 80457 family is known for being a vacuum secondary carb with an electric choke, which makes it very street friendly and easy to live with. The 3303 number you see is a secondary production or date code and does not change the core identification of the carb itself. Based on that list number, you are working with a 600 cfm Holley 4150 style carburetor, which is a very popular size for mild to moderate performance engines. If you ever need parts or tuning components, you will want to reference the Holley 4150 series when searching. If you would like help dialing it in or making sure it is set up correctly for your engine, give us a call at 1-800-345-4545 and speak with a Tech Specialist and we will be glad to help.
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Pete Mitchell: Last question Pete, can you provide the part number for this throttle plate? I have the Ford kick down linkage and I think the only plate that will work is the 112-117. Do you agree?
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Good question, and you are right to double check before you spend money on a baseplate.
Based on what you have told me so far, I can say this much with confidence: you have a 4150 vacuum secondary carb with 1.625 primary and secondary bores, set up with Ford kickdown linkage. That means you need a 4150 style Ford kickdown baseplate for a 750 style carb, not a 780 style piece. I cannot positively confirm that the specific Holley part number you mentioned is correct without direct access to Holley’s current catalog and your exact carb in front of me, so I do not want to tell you “yes” and have it turn out to be wrong. The safe way to nail this down is to have the list number 83310, your bore measurement of 1.625 inches, and the fact that it has Ford kickdown linkage checked directly against Holley’s baseplate listings.
If you give that info to our tech team, they can cross reference it with Holley and make sure you get the right Ford kickdown 750 style 4150 base. You can reach them at 1-800-345-4545 and a tech specialist can verify the exact replacement before you order.
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For Pete Mitchell, the 4150 carb is stamped 83310, Date code 2191. I couldn’t find a number on the throttle plate. You mentioned 2 different size primary/secondary bore size but mine is 1.625 or 1 5/8″ Stamped on the throttle plates is the number 172. Is this enough info to specify the new plate?
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Dan, that extra info helps a lot. With the 83310 being a 4150 style carb and you confirming the throttle bores measure right at 1.625 inches, that tells us you’re working with the standard 750 style base. The “172” you found on the throttle blades is a blade stamp, not the baseplate ID, but between the list number, the bore size, and the fact that it’s a vacuum secondary 4150, there’s enough to narrow it down.
Holley offered both small bore and large bore baseplates on certain list numbers, which is why I mentioned both earlier, but your measurement rules out the 780 style. A 1.625 bore is the common 750 configuration, so you’d be looking for a 4150 style replacement baseplate that matches that size. As long as the replacement is for a 750 style 4150 vacuum secondary carb, it will match your dimensions and the spacing for the throttle shafts.
The only thing I can’t confirm without seeing the original plate is whether yours uses the standard or Ford style kickdown linkage pattern, but if the carb was rebuilt by Holley and has the add on kickdown bracket installed, you’re almost certainly dealing with a standard 4150 pattern baseplate.
If you want to double check anything before you order, feel free to call us at 1-800-345-4545 and a tech specialist can walk through the details with you.
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Quick question, I have a Holley Carburetor, List 83310, date code 2191, which I understand to be a 750cfm aftermarket carburetor from the 21st week of 1991? I had it rebuilt by Holley last year and it is now installed with the appropriate kick down add-on, on a Ford 429 with a C6 transmission. It leaks from the secondary throttle shaft and I believe that the only available fix is to replace the base plate. Can you provide the correct part number for this carburetor?
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Hi Dan, you’ve got the details right about your carb. A Holley list 83310 with a 2191 date code is a 750 CFM vacuum secondary carb built in the twenty first week of 1991. That matches what you were told.
As for the leak at the secondary throttle shaft, you’re right that once the shaft bushings are worn, the long term fix is to replace the base plate. Holley does not bush these plates from the factory, so when they get sloppy, fuel will seep through the shaft area just like you’re seeing.
The only thing that makes it tricky is that Holley produced a few variations of the 83310 over the years, so there isn’t one single base plate that automatically fits every one. To identify the correct replacement, we would need one more piece of information: the throttle bore size stamped on the underside of the base plate or the casting number on the bottom plate itself. Holley used both 1.375 and 1.560 throttle bores in different versions of similar 750 CFM vacuum secondary carbs, and that determines which base plate series you need.
Once we know that measurement or the casting number, we can match it to the right Holley replacement plate available through JEGS.
If you want to be sure and avoid guessing, give us a quick call at 1-800-345-4545. A tech specialist can confirm your throttle bore size and make sure you get the correct base plate for your 83310 so you can put that leak behind you.-
I believe you are incorrect about your date code id. The 4 digit date code is actually the 219st. day of 1981, 1991, 2001, 2011,or 2021. This started in 1973 to current. This is straight from Holley.com. Thank you.
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Hi Bill, thank you for the clarification and for taking the time to comment. You are correct that Holley uses a four digit Julian style date code, where the first three digits indicate the day of the year and the last digit represents the year within a decade. Where the confusion often comes in is that the final digit alone does not identify the decade by itself.
Holley has long stated, and this is also covered in the Holley Carburetor Handbook by Mike Urich and Bill Fisher, that the actual decade must be determined by referencing the LIST number and the known production window for that specific carburetor. In other words, the date code and the LIST number must be used together.
In this case, LIST 83310 is a documented aftermarket vacuum secondary carburetor that was produced in the late 1980s into the early 1990s. It was not in production in 1981. That production history rules out earlier decades, which makes the date code 2191 correctly decode to the 219th day of 1991.
If you would like to research this further, good references include Holley’s own tech documentation, the Holley Carburetor Handbook by Urich and Fisher, and published Holley LIST number reference data that shows when specific LIST numbers were introduced and discontinued. Long standing carburetor reference databases such as Squirrel Performance also cross reference LIST numbers with production eras and support the same conclusion.
We appreciate the discussion and the opportunity to clarify how Holley date codes and LIST numbers work together.
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I have a Holley list 83310 stamped 2970 underneath the 83310. It’s a square bore vacuum secondary with manual choke and dual fuel inlet. I was told it was a 780 cfm but believe it may be a 750. Do you know the details on it?
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Hi Lloyd, great question. The Holley carburetor with LIST 83310 and the date code 2970 you mentioned is a 750 CFM 4150-style vacuum secondary carburetor, not a 780. It was produced around 1970 and typically came with dual fuel inlets, a manual choke, and a square bore flange pattern, which fits most standard 4150/4160-style intake manifolds.
This model is part of Holley’s 4160 series lineup, which uses a metering block on the primary side and a metering plate on the secondary side. The 780 CFM units were generally used on factory performance models like the early Chevrolet Z/28 or Corvette 302/327/350 engines, while the 83310 was built as an aftermarket or universal performance replacement carb rated at 750 CFM.
If you’re planning to rebuild it, you’ll want a Holley 4160-style rebuild kit. The correct kit depends on the exact gasket style and fuel bowl configuration, but Holley and Quick Fuel both make universal kits that match your carb setup.
If you’d like to confirm the right kit and options for your engine build, give us a call at 1-800-345-4545 and speak to a JEGS tech specialist. They can verify all the details and help you pick the right rebuild components.
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Hi. Have a hot rod with a white performance racing engine and a Holley quick fuel carb. I can’t seem to locate any part number stamped on the carb so I’m stumped on what carb rebuild kit to order. I’d guess it’s a 650 CFM but really not sure. If the part number is stamped on the under side of the carb that’s why I haven’t located it as I have only removed the carb bowls and replaced the accelerator pump and carb bowl gaskets to date. Will I find the part number on the bottom of the carb?
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Hi Bill, great question. On Holley and Quick Fuel carburetors, the part or list number is not stamped on the bottom side of the carburetor. Instead, you’ll usually find it stamped on the air horn (the flat surface right above the choke plate) or, in the case of some Quick Fuel models, on the front of the main body near the choke tower. If your carb doesn’t have an air horn or the stamping is faint, you can often still identify it by looking at details like the throttle bore size, metering block style, and fuel bowl type.
Since you’ve already replaced the accelerator pump and bowl gaskets, you’re halfway there. The rebuild kit you’ll need depends on the exact carburetor model, and while most Quick Fuel and Holley 4150 or 4160 series units share similar gasket patterns, there are differences in needle and seat assemblies and power valve styles that make it important to confirm which one you have before ordering.
If you can’t locate any numbers, try checking for a small aluminum tag under one of the fuel bowl screws. That tag sometimes carries the model information. If it’s missing or unreadable, you can measure the throttle plate bores or take a few clear photos of the main body and metering blocks to help identify it.
You can call us at 1-800-345-4545 and speak to one of our tech specialists who can walk you through identifying your carb and help you get the exact rebuild kit you need.
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I have a Holley with a list number 4118 and a date code 3381. I’m a little confused as to what I have. Some sources say 700, some 715, I’ve also see it listed as a Shelby GT 350 carb. I’m skeptical to say the least. Can you help?
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Hi Dan, great question, and you’re not alone in being a little unsure about that carb. The Holley List-4118 is indeed a bit of a special one. That carburetor was originally used on 1965–1966 Shelby GT350 Mustangs equipped with the 289 Hi-Po engine. It’s a 715 CFM Holley 4160-series carburetor with a center-hung float bowl, mechanical secondaries, and no choke housing.
The confusion you’re seeing online comes from the fact that the 4118 shares a lot of internal similarities with other 700–715 CFM Holleys from that era, but its specific calibrations and parts were tailored for the high-performance 289. The date code you gave, 3381, means it was produced in the 33rd week of 1981, which makes it a service replacement carburetor rather than an original 1960s unit. Holley continued to produce service versions of popular performance carbs for years after the originals were discontinued.
So, in short, yes, the List-4118 was originally a Shelby GT350-spec 715 CFM Holley, but based on your date code, yours is a later production version, not the one that would have come on a 1965–66 car from the factory.
You can call us at 1-800-345-4545 and speak to one of our tech specialists if you’d like to confirm calibration details or need help selecting the right rebuild kit for it. They can also help verify which components match your exact carb body and setup.
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Que mas Bill,
Presento dificultades para encontrar el Kit de Repuesto para un carburador Holley. El estampado en su primera línea las cuatro primera letras se encuentran poco visibles, algo parecido a DEHF – 9510 – CA, la segunda línea es LIST – 6548 y la tercera 2792.
Este carburador está montado en un Ford Falcon del 66 con un motor 289.
Como soy el tercer propietario del vehículo quisiera saber si el carburador en mención es el que viene configurado de fabrica para este motor.
Gracias por tu ayuda-
Julio, thanks for the detailed information you included, that makes things much clearer. The number you provided, LIST-6548, tells the story here. That list number corresponds to a Holley 2-barrel carburetor that Ford used on certain applications in the late 1960s. For your 1966 Falcon with the 289 V8, this carburetor is not the exact one that would have been installed from the factory. Ford typically fitted the 289s with Autolite carbs, not Holleys, unless the engine was swapped or modified by a prior owner.
The fact that yours has a Holley doesn’t mean it’s wrong or a bad match, it just means somewhere in the car’s history a previous owner or mechanic decided to upgrade or replace the original carb. Many people chose Holleys for reliability and tunability. So while it is period-correct in terms of era, it’s not the Falcon’s stock carb.
As for your rebuild kit, since Holley parts are matched by the list number, you’ll want to search for a kit designed specifically for LIST-6548. That will give you the correct gaskets, seals, and small parts needed for a proper rebuild. The faint stamping you mentioned on the first line doesn’t change the identification, the list number is the key here.
If you’d like to go over exactly which rebuild kits and replacement options we can set you up with, I’d recommend giving our tech line a call. You can reach a specialist at 1-800-345-4545, and they’ll walk you through everything step by step to make sure you get the correct parts for your Falcon.
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Hello, I need a rebuild kit for my Holley marine Carburetor
SAE J1223
30559-1
1642
Please let me know which rebuild kit I need to order?
Thanks-
Hi Robert, thanks for sharing the carb information. Based on the numbers you listed, you have a Holley marine carburetor with the stamping 30559-1. That number identifies it as a specific Holley marine model, and rebuild kits for marine carbs are different than automotive kits because of U.S. Coast Guard requirements for fuel safety.
To get the exact rebuild kit, you’ll want to match that list number (30559-1) rather than the SAE number since Holley catalogues their service parts by the list number. The “1642” is just a date code, not part of the kit identification. Because it’s a marine carb, you’ll need to make sure you’re using a Holley marine-specific rebuild kit, as those include the correct gaskets, seals, and vent baffles required for safe use in a boat.
If you’d like to order the right kit, I’d recommend giving us a quick call with that list number handy. That way, we can confirm stock and ensure you get the correct marine rebuild kit for your carburetor. You can reach our tech specialists at 1-800-345-4545, and they’ll be glad to set you up with the right parts.
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LOOKING FOR REPLACEMENT OR REBUILD KIT FOR A HOLLEY CARB, NOT SUER WHAT I NEED THIS IS WHAT STAMPPED INTO THE CARB
HOLLY
R 7871 A
1047585
2697THANKS
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Hi Doug, thanks for sharing the numbers stamped on your Holley carb. Based on what you listed (R 7871 A / 1047585 / 2697), this looks like an older Holley unit that was originally built for OEM use. The “R” prefix is Holley’s standard way of stamping a list number, which is what you’ll need to identify the correct rebuild kit. The number 7871 is the list identifier, and from there Holley’s charts cross it to a specific application.
For replacement or rebuild kits, the good news is that Holley rebuild kits are grouped by list number series, not just by vehicle. That means you don’t have to worry about all the extra casting numbers, just the list number. Since you’ve got R7871, that points you toward a Holley 4150/4160 style rebuild kit that covers your list number range. You’ll want to confirm whether your carb has a primary metering block and a secondary metering block or a metering plate, since that changes which rebuild kit family it falls into. If you’re not 100 percent sure, the tech line or catalog cross reference will match it for you before purchase.
If your goal is just a rebuild, you’ll be fine using a Holley brand kit that specifically lists compatibility with the 7871 carb. If you’re looking for a direct replacement carb instead, you’d be better off considering a new Holley Street or Performance series carb sized appropriately for your engine, since finding a brand new identical 7871 is unlikely.
To be 100 percent accurate, the one piece of information I’d still want to confirm is whether your carb is a 4150 or 4160 configuration, since that detail matters when ordering the rebuild kit. Once you know that, you’ll have exactly what you need.
For the quickest path to the right part, I recommend giving our tech specialists a call at 1-800-345-4545 and they can match you to the correct Holley kit or a replacement carb option if you decide to go that route.
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I just picked up a holley from a family friend. Can’t find anything about the list or model #’s. Any information on what it’s from and what rebuild kit I need to buy.
3868864
LIST-3140-1
572-
Hi Evan,
That Holley you have with LIST-3140-1 and the casting number 3868864 is actually a GM factory-spec Holley carburetor. It was originally used on 1968–1969 Chevrolet big block engines, specifically the 427 cubic inch motors in Corvettes and other high-performance Chevys. The “572” you see stamped is just an internal Holley identification code and not related to displacement.
The LIST-3140-1 confirms it as a Holley 4150 series, 750 CFM double pumper, calibrated for GM. Because it’s a GM-specific version, it does have some unique calibration features compared to an aftermarket Holley, but for rebuild purposes it still falls under the standard Holley 4150 rebuild category. You’ll need a Holley 4150-style rebuild kit that covers the dual metering blocks and accelerator pump setup. Holley and other performance brands still offer these kits, and they’re widely available. JEGS offers them with the following part numbers: 555-150260 (JEGS Brand) 510-37-485 (Holley Brand).
Since your carb has been sitting, it’s a good idea to also check the throttle shafts for play, inspect the float bowls for warping, and verify the boosters are clean. If it’s in good shape overall, a proper rebuild kit will get it running strong again.
If you need additional help, call us at 1-800-345-4545 and speak to a JEGS tech support specialist.
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hola tengo un carburador holley me dijeron que es 850 tiene un numero en la entrada de aire es 6 R 5533 B me podrá ayudar a saber cuel es y con cual numero puedo encontrar algún repuesto para el mismo
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Hi Juan,
The number you provided, R 5533 B, identifies your Holley carburetor as part of the Holley 4150 series. That particular number matches up to an 850 CFM double pumper carburetor. The “6R” in front is simply a Holley engineering prefix, while “5533B” is the actual list number.
When it comes to replacement parts, what you’ll want to use as a reference is the list number (5533B). That is how Holley catalogs their rebuild kits, gaskets, and tuning components for your carburetor. The stamped number on the air horn is always the most reliable way to identify the correct service parts.
If you need help finding the exact kit or the right jets, power valves, or gaskets for that carb, give us a call at 1-800-345-4545 and one of our tech specialists will walk you through the best match for your setup.
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Hello,
Older Holley carb I been running on a warmed over 327 chevy.
List number is 4778. Also a 3043 stamped underneath it.
I was told its a 750 but believe its a 700 cfm.
Please confirm.
Thank you,
Bill-
Hi Bill,
Your Holley carburetor with a list number of 4778 is a 700 CFM double pumper model. The 4778 series was built as a mechanical secondary carb and is not a 750 CFM unit, so your suspicion is correct. The 3043 number you see is likely a date or batch code used by Holley for production reference, not related to the CFM rating.
If you want to be absolutely sure about any other details, such as exact production year or internal specs, you can confirm by checking with Holley’s tech department or referencing their historical carb list guides.
If you’d like, give us a call at 1-800-345-4545 and speak to a tech specialist who can walk you through more details about your specific carb and help with tuning or replacement options.
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Can you help me ? I have a homey performance carb list #86670-1 date code #0743 ,it is on a 350 and in my 1975 Corvette C3 Stingray , I have searched everywhere but nothing about it that I can find . Thank you so much Scott H Smoot Sr
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Hi Scott,
Your Holley carburetor with List #86670-1 and Date Code #0743 is a performance-series carb, but detailed records on this specific list number seem to be limited. Typically, Holley list numbers identify the exact model and specifications of the carb, while the date code (0743) follows Holley’s standard format, indicating it was produced by the following example: 0743 > 074- Day of Year (would land in March) , 3 – 1973/1983/1993/2003/2013/2023. Since it’s installed on your 1975 Corvette C3 with a 350 engine, it’s likely a Holley aftermarket replacement carb rather than an OEM factory-installed unit. The “86670” series number suggests it could be a 670 CFM Street Avenger or similar model, designed for street-performance applications with features like vacuum secondaries and an electric choke. To confirm the exact specs, I recommend checking the choke housing and metering block numbers and comparing them with Holley’s catalog or contacting Holley’s tech support. JEGS Tech Support at 1-800-345-4545 can also help you find the best match. Hope this helps, and enjoy your Stingray!
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Hi I have a holley on a 396. and I am trying to get some information on it . any help would be appreciated On my air horn it is stamped 80508-1 under that stamp is another stamp and it is 2481 . I cant find any information on the 2481 . I do believe it to be an older Holly.. I has the double fuel line hookup . Please help Billy
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Hi Billy,
You’ve got a Holley carburetor with the stamping 80508-1 on the air horn, and you’re trying to identify it and understand the 2481 marking. Let’s break this down for you.
Identifying Your Holley Carburetor (80508-1)
Holley List Number: 80508-1
The 80508-1 is a Holley 750 CFM, vacuum secondary carburetor, commonly part of the 4160 series.
It’s a spread bore-style carb, often used as a replacement for Quadrajets or other factory-style carbs on big-block engines.
This carb is a great fit for your 396 big-block Chevy, as 750 CFM is a solid size for performance applications.
It features electric choke and dual fuel inlets, making it a good street/strip option.
What Does the “2481” Stamp Mean?
The 2481 is the date code, which tells when the carburetor was manufactured.
Holley date codes are usually in a four-digit format, where:
The first three numbers represent the day of the year it was built.
The last digit represents the year of production (within a given decade).
Possible Interpretation of 2481:
248th day of a year ending in “1” (e.g., 1971, 1981, 1991, etc.).
Since your carb is an older model, it was likely made on the 248th day of 1981 or 1991.
Additional Notes for Your 396 Setup
Your 396 big-block Chevy likely benefits from this 750 CFM Holley 4160, as it provides a good balance of airflow and fuel delivery.
If you plan on tuning it, check:
Primary and secondary jet sizes (typically around 72-76 primary, 80-84 secondary, but may vary).
Vacuum secondary spring tension (lighter springs allow secondaries to open quicker).
Idle mixture adjustments to fine-tune response.
Final Thoughts
Your Holley 80508-1 is a 750 CFM vacuum secondary carburetor, ideal for your 396 big-block Chevy. The 2481 date code suggests it was manufactured on the 248th day of a year ending in “1” (likely 1981 or 1991).
If you need further details on tuning or rebuilding, feel free to contact JEGS Tech Support at 1-800-345-4545. Hope this helps, and happy wrenching!
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