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 Small Block Chevy 350ci engine, except 1992-1997 LT1 style engines

Bulletproof bottom end built to handle more power with its top of the line parts. 

Block Information:

• Seasoned OE 4 bolt main 1-piece rear main seal 1996-2000 roller block, passenger side dipstick
• Bore/Stroke: 4.040 in. x 3.750in.
• Displacement: 383 ci
• Camshaft Bearings: Dura-Bond, installed and clocked to OEM position
• Freeze Plugs: Brass, installed and sealed
• Oil Galley Plugs: Installed and sealed

Rotating Assembly:

• Crankshaft: 4340 forged
• Balance: External rear (flexplate/flywheel), internal front (harmonic balancer)
• Rods: Scat 5.700 in. 4340 forged H-beam with 8740 ARP bolts 
• Compression Ratio: 58 cc= 10.4:1 64 cc= 9.8:1 / 70 cc= 9.2:1 
• Pistons: 2618 forged -16 cc dished with 2 valve reliefs
• Rings: Plasmamoly
• Flexplate: External balance 168-tooth

  Recommended Components:

• Balancer: Internal balance
• Flexplate/Flywheel: External balance (1987-Up 1 piece rear main)
• Head Gasket: .038 in. thick or per application
• Oil: 10W30 Non-synthetic for first 3000 miles
• Oil Filter: Wix or K&N per application

Please CLICK HERE for ATK Warranty