Edelbrock Performer RPM 2-O Intake Manifold for Chevrolet 396-502 Big-Block V8Edelbrock part #7161 Performer RPM 2 O intake manifold is designed for street 396 502 c. i. d. Chevy V8's with large oval port cylinder heads (1975 and earlier). This dual plane high rise intake manifold delivers outstanding horsepower while maintaining good torque and driveability. No provisions for exhaust heated chokes. Accepts late model waterneck, air conditioning, alternator and HEI equipment.