Performer RPM Cylinder Head #61035 for Oldsmobile Small Block Set/2

Can optionally be milled for 1/2 head bolts to fit the 403 Olds found in some 1978-80 Pontiac Tran Ams

***When using the 61035 Big Block Olds head on a 403, the 7111 intake with port matching will be required***

Intended for installation on 1965-1976 Small-Block Oldsmobile 350-403 c.i. engines equipped with a hydraulic roller camshaft, these 356-T6 aluminum casting cylinder heads (#61035) are a modern refinement to our #6051 heads, except they can accommodate a factory-style mechanical fuel pump. A smaller 68cc combustion chamber achieves a more appropriate small block compression ratio compared to our #61025/61029’s larger 77cc chamber, which yields a lower compression ratio than most engine builders desire on a small block engine.

These heads require a 3.9375” minimum bore and feature a modern chamber design with optimized spark plug positioning. Maximum airflow is achieved through the factory 6° valve angle using high-flow 200cc intake and 130cc exhaust port volumes, along with 2.072” intake and 1.680” exhaust valve sizes in their O.E. positions. A 5/8” finished deck thickness with added material above the intake port and pre-counterbored head-bolt holes for 1/2” diameter studs provide extra clamping force in key areas. A stud-and-guide plate valvetrain system (as opposed to the O.E. pedestal type) provides a solid foundation for the beefier 3/8” diameter pushrods, and Helicoil inserts in the exhaust and rocker stud holes keep bolts secured. However, there are no provisions for a heat crossover.

Although these heads will fit on Big-Block Oldsmobile engines, the 68cc combustion chamber size is not ideal for a big-block application as it will raise compression. See #61025 and #61029 (Flat Tappet) for big-block specific cylinder heads.