5658 Small Block Chevy 355ci/300HP Crate Engine

Vehicle Info Needed

ATK ENGINESPART NUMBER: 059-5658

5658 Small Block Chevy 355ci/300HP Crate Engine

Name: 5658 Small Block Chevy 355ci/300HP Crate Engine
Brand: ATK ENGINES
SKU: 059-5658
Price: 2998.49 USD
Availability: InStock

^$2,998⁴⁹

Core Charge: ^$510⁰⁰

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355ci Crate Engine

Small Block Chevy 355ci/300HP Crate Engine

Pre-1986 Cast Iron Cylinder Heads

Compare to GM Engine 19355658

Perimeter Bolt Style Valve Covers

1-Piece Rear Main Seal

2-Bolt Mains -Long Block

24 Month/Unlimited Mileage Warranty

ATK Core Return Process
JEGS and ATK appreciate your business and want to ensure that your core return is as smooth as possible.

Please CLICK HERE for ATK Core Return Process

NOTE:

Core return can be any 1967-2000 Small Block Chevy 350ci engine, except 1992-1997 LT1 style engines

Engine Specifications

Power Ratings:

Factory Specs
- Horsepower: 300
- Torque: 360 lb/ft

Block Information:

1987-1995 seasoned OE block
2-bolt main
1-piece rear main seal
Passenger side dipstick
Displacement: 355 cubic inch

Rotating Assembly:

Crankshaft: OE reground cast 1-piece seal
Balance: External rear (requires 1987-Up style flexplate or flywheel), internal front
Rods: OE reman powder metal 5.700 in.
Compression Ratio: 8.5:1
Pistons: Cast
Rings: Moly

Camshaft Specs:

Camshaft: Hydraulic flat tappet
Cam Duration @ .050": Intake 224 / Exhaust 224
Cam Lift: Intake .466" / Exhaust .466"
Lobe Separation Angle: 114
Timing Chain: Single roller

Cylinder Head Information:

Cylinder Heads: Pre-1986 cast iron
Combustion Chamber: 76cc
Valve Size: 1.94" Intake / 1.50" Exhaust
Rocker Arms: Stamped steel 1.5

Oil Pan Information:

Oil Pan: Black 4 quart
Oil Pump: Melling standard volume

Long Block Includes

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

Notes: If replacing a pre-1987 (2-piece rear main seal) engine, a new external balance flexplate/flywheel for 1987-Up style engines will be required. This engine will also require a passenger side dipstick (1980-Up vehicles). Driver's side dipstick will not work (Pre-1979). This engine has provisions for a mechanical fuel pump. Will require stock style spin-on oil filter adapter 555-23605 or equivalent.

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.

Please CLICK HERE for ATK Warranty

Performance Inspired and Designed by Crate Engine Specialists

JEGS Small Block Chevy 355 Crate Engine is reverse engineered to create a product that has better-than-new quality. Reverse engineering allows any factory original defect to be found and removed, saving you time and money by keeping your vehicle out of the shop and on the road. Engines are factory checked after assembly to ensure proper operation. This engine features a 24 month/unlimited mileage warranty.

Take your project to the next level with the JEGS Small Block Chevy 355ci/300HP Crate Engine, a powerful and reliable upgrade for classic car enthusiasts, hot rodders, and performance builders. This turn-key crate engine delivers a perfect balance of streetable horsepower and long-term durability—making it an ideal choice for anyone seeking dependable performance right out of the box.

Built with all-new components—not remanufactured parts—this engine features a 2-bolt main block, cast iron cylinder heads, and a high-performance hydraulic flat tappet camshaft to produce a solid 300 horsepower and 380 ft.-lbs. of torque. The 355 Chevy engine gives you more displacement than a traditional 350, resulting in extra punch without compromising reliability.

As a direct-fit solution for many GM vehicles, this 355 crate motor simplifies your build and minimizes downtime. Whether you're restoring a vintage muscle car, upgrading a weekend cruiser, or building a street machine from the ground up, this engine delivers the performance you need with the peace of mind that comes from JEGS' trusted craftsmanship.

Ready to feel the power difference? Choose the JEGS 355ci/300HP Crate Engine and make your next build your best one yet. Order today and get back on the road with confidence.

Part TypeEngine

Product LineJEGS Small Block Chevy 355ci/300HP Crate Engine

BrandATK ENGINES

Package Height24.75

Package Width29.75

Package Length30.5

Weight420.0 PG

Part CategoryReplacement Parts

Wiring Harness IncludedNo

Spark Plug Wires IncludedNo

Cylinder Head MaterialCast iron

Air Cleaner IncludedNo