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ATK Engines HP94M

ATK Engines High Performance Crate Engine Small Block Chevy 383ci / 425HP / 470TQ


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ATK Engines High Performance Crate Engine Small Block Chevy 383ci / 425HP / 470TQ $4,170.00
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High Performance Crate Engine
  • Small Block Chevy 383ci
  • 425HP / 470TQ
  • Mid Dress Engine
  • Items You May Also Consider

    ATK Engines HP94M Details

    Mid Dress Engine

    Engine Info

    • Balancer: Internal balance
    • Distributor: HEI (iron gear)
    • Exhaust: 1-5/8" Headers
    • Firing Order: 18436572
    • Flexplate: External balance
    • Intake Manifold: Weiand Stealth dual plane #925-8150
    • Octane: 91+
    • Oil: 10W30 (Conventional / Non Synthetic) 
    • Oil Filter: Wix or K&N
    • Spark Plug Gap: .035"
    • Stall Converter: 2200-2800
    • Timing: 34-36 Degrees 
    • Water Pump: OE long pump

    Recommended Components

    • Carburetor: Quick Fuel 680cfm vacuum secondary electric choke #793-HR-680-VS
    • Fuel Pump: Holley Mechanical 110gph #510-12-327-11
    • Spark Plugs: Autotile #417-3923
    • Spark Plug Wires: 8mm


     Disclaimer: The parts listed are ATK's recommendations of parts to be used to obtain the power figures listed. Power figures can vary based on parts used by the end user. Some modifications to the vehicle may be required using these and or other aftermarket parts.

    Engine Break-In Procedure

    Use or break-in oil or conventional (non-synthetic) 10w30 oil with zinc additive for the first 500 miles of operation.  Do not drive for long periods at any single speed, always vary your speed. Do not tow a trailer or put other heavy loads on the vehicle. It is best to avoid long periods of idling during this period. Check the engine oil and coolant levels daily. 

    Engines with flat tappet hydraulic cams only - Run the engine between 2,000 and 2,500 RPM's, with no-load on the engine for the first 30 minutes. Let the engine cool down completely and repeat process 2-3 more times. Do not idle the engine for any extended period at this time, this is critical to break in the camshaft.

    At 500 Miles change the engine oil and filter using conventional (non-synthetic) oil with a zinc additive. Check fuel and ignition settings, adjust valves (where applicable).  Drive the next 500 miles normally, without high RPM's (below 5000 RPM), hard use, or extended periods of high loading or long periods of idling.

    Change the oil and oil filter again at 1,000 miles. Continue using conventional (non-synthetic) oils and zinc additive, until about 4,000 miles. At that point, you may run a quality 10w30 synthetic oil if you choose. Use of oil with zinc or a zinc additive for the life of your engine is recommended. 



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    383 Stroker Performance

    In 2007, ATK launched a High-Performance Division with one of the finest engine shops in the country. By reverse engineering all of their engines, they are able to eliminate any OEM deficiencies, providing an ATK built crate engine a superior design over the original engine by incorporating better components when needed. Quality build ATK Chevy engines are offered in three different stages for ease of finishing an engine swap. ATK HP engines feature a 24 month/unlimited mile warranty.

    Engine Specifications

    • Horsepower: 425 hp
    • Torque: 470 ft.-lbs.

    Block Information:

    • Seasoned OE 4 bolt main 1pc seal 1996-2000 
    • Bore/Stroke: 4.040 in. x 3.750 in.
    • Displacement: 383 ci

    Rotating Assembly:

    • Crankshaft: Scat nodular iron
    • Balance: External rear, internal front
    • Rods: Scat 4340 forged I Beam 5.7 in. with ARP 8740 bolts
    • Compression Ratio: 9.7:1
    • Pistons: Hypereutectic
    • Rings: Moly

    Camshaft Specs:

    • Camshaft: Hydraulic roller
    • Cam Duration @ .050 in.: Intake 220 / Exhaust 224
    • Cam Lift: Intake .528 in. / Exhaust .536 in.
    • Lobe Separation Angle: 110 LSA
    • Timing Chain: Double roller

    Cylinder Head Information:

    • Cylinder Heads: Dart SHP
    • Combustion Chamber: 64 cc
    • Intake Runner: 180 cc
    • Valve Size: 2.02 in. Intake / 1.60 in. Exhaust
    • Rocker Arms: Biller aluminum roller rockers 1.6 ratio

    Oil Pan Information:

    • Oil Pan: Rear sump 5qt (not for Chevelles with steering behind crossmember, some Corvettes, and 1962-1967 Chevy II's
    • Oil Pump: Melling standard volume

     Base Engines

    • Short Block
    • Camshaft
    • Timing Set
    • Cylinder Heads
    • Valve Covers
    • Timing Cover
    • Oil Pan
    • Oil Pump & Pickup Tube
    • Flexplate

    Mid Dress Engines

    • Consists of Base Engine Build
    • Intake Manifold
    • Distributor
    • Water Pump 
    • Harmonic Balancer

    Complete Engines

    • Consists of Mid Dress Engine Build
    • Fuel Pump
    • Carburetor or EFI 
    • Spark Plug Wires
    • Spark Plugs

    JEGS Easy Kits are designed by JEGS high performance racing professionals to help you get all the performance parts you need for your race car, hot rod or truck.

    Dose this engine has a nice looping sound at idle 

    Asked by: Illah
    This engine will have a noticeable idle.
    Answered by: Rusty B
    Date published: 2018-10-02

    What flywheel/flexplate do I need for this motor? I will be running a turbo 400 behind it.

    Asked by: Shane13
    This is the recommended flexplate - https://www.jegs.com/i/JEGS-Performance-Products/555/601072/10002/-1
    Answered by: Rusty B
    Date published: 2018-06-06

    Can this engine come with Polish intake manifold Chrome polished And how much

    Asked by: Bruce 57
    No, it is only available as you see it in the image.
    Answered by: Rusty B
    Date published: 2018-04-18

    Is the block drilled for a clutch ball?

    Asked by: txfatboy
    These blocks do have a boss for the clutch ball.
    Answered by: Rusty B
    Date published: 2018-02-28
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    Some parts are not legal for use in California or other states with similar laws / regulations

    Motor Vehicles

    WARNING: Motor vehicles contain fuel, oils and fluids, battery posts, terminals and related accessories which contain lead and lead compounds and other chemicals known to the State of California to cause cancer, birth defects and other reproductive harm. These chemicals are found in vehicles, vehicle parts and accessories, both new and as replacements. When being serviced, these vehicles generate used oil, waste fluids, grease, fumes and particulates, all known to the State of California to cause cancer, birth defects, and reproductive harm.


    WARNING: Some dust created by power sanding, sawing, grinding, drilling, and other construction activities contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Some examples of these chemicals are: lead from lead-based paints, crystalline silica from bricks and cement and other masonry products, and arsenic and chromium from chemically treated lumber. Your risk from exposure to these chemicals varies, depending on how often you do this type of work. To reduce your exposure, work in a well-ventilated area and with approved safety equipment, such as dust masks that are specially designed to filter out microscopic particles.

    Electrical Cords

    WARNING: The wires of these products contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Wash hands after handling.