Xe285hl cam

Should have bought the larger 65 cc edelbrock heads.

IIRC, the “63cc” head will typically measure 64 cc.

Have a 416 with a similar 274-S cam with 9.7:1 measure compression and im on the edge of pinging with 91 octane pump gas.

Sounds like you had a plan...then the machinist cut into your heads.