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.