⚠ No shipping to California due to CARB regulation.
Intended for installation on 1965-1976 Small-Block Oldsmobile 350-403 c.i. engines equipped with a flat tappet camshaft, these 356-T6 aluminum casting cylinder heads (PN61039) are a modern refinement to our PN6051 heads, except they can accommodate a factory-style mechanical fuel pump. A smaller 68 cc combustion chamber achieves a more appropriate small block compression ratio compared to our PN61025/61029’s larger 77 cc 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-degree valve angle using high-flow 200 cc intake and 130 cc exhaust port volumes, along with 2.072” intake and 1.680” exhaust valve sizes in their O.E. positions. A finished deck thickness with added material above the intake port and pre-counterbored head-bolt holes for .5” 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 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 68-cc combustion chamber size is not ideal for a big-block application as it will raise compression. See PN 61025 and PN 61029 for big-block specific cylinder heads.
For 350-403 c.i. Olds engines with a flat tappet cam, these heads are made of 356-T6 aluminum with 68 cc chambers, high-flow 200 cc intake and 130 cc exhaust port volumes, and 2.072” intake and 1.680” exhaust valve sizes.
| Years | Make | Model | Trim |
|---|
| Air Freight Prohibited: false |
| Not Carb Approved: true |
| Carb Acknowledgement Required: true |
| Ltl Freight Required: false |
| Prop 65: Y |
| Part Type: automotive |
| Epa: N/A |
| Regular Stock: false |
| Units Per Sku: 1 |
No fitment data available for this product.
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