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

JEGS crate engines are 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. Every engine is issued a certificate for testing compression, oil pressure, and water temperature. JEGS crate engines feature a 36 month/unlimited mileage warranty.

This engine is designed as a universal, budget replacement engine for most GM vehicles or can be retrofitted into virtually any vehicle or hot rod. Producing up to 195hp using an OE carburetor, intake and exhaust manifolds, this engine can make up to 260hp with headers, performance intake manifold and a 4-bbl carburetor.

Engine Specifications

Power Ratings:

• Factory Specs
  • Horsepower: 195 
  • Torque: 300 lb/ft

• Engine with Performance Accessories
  
  • Horsepower: 260*
  • Torque: 300 lb/ft*

*Tested using a performance dual plane intake manifold, 670cfm carburetor, headers, and a HEI distributor.

Block Information:

• 1987-1995 seasoned OE block
• 2 bolt main
• 1 piece rear main seal
• Passenger side dipstick 
• Displacement: 350ci/5.7L

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 5.7"
• Compression Ratio: 8.6:1
• Pistons: Cast
• Rings: Moly

Camshaft Specs:

• Camshaft: Hydraulic flat tappet
• Cam Duration @ .050": Intake 194 / Exhaust 202
• Cam Lift: Intake .390" / Exhaust .410"
• Lobe Separation Angle: 112
• 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.

Engine Break-In Procedure

Use conventional or break-in oil (non-synthetic) for the first 600 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. Check the engine oil and coolant levels daily. 

At 600 Miles change the engine oil and filter using conventional (non-synthetic) oil. Check fuel and ignition settings; adjust valves (where applicable).

After the first 5,000 of service synthetic engine oil may be used. Follow your vehicle owner’s manual for service intervals.

Please CLICK HERE for ATK Warranty