Power pack heads? Looks like I only have one power pack head. So this might mean I have a mismatch of heads.
The DS has the casting mark with a rectangle and with a pointy triangle on top. The PS has the rectangle.
This website shows what the casting marks indicate. SBC heads casting marks
If the heads are as different as the chart shows, then the compression will be different too (according to the chart).
Should I pull the heads?

Last edited by Lugnutz; 03/15/2021 12:18 AM.
1965 Chevy C10 Shortbed 1/2-Ton Stepside
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