Edelbrock heads on a 340 with KB243 pistons

[yellow rose]

I'm not following this.... maybe it's being missed that he already has the closed chamber heads. The CR is being limited by the chamber volumes and piston to head clearance, not by the positional relationship of the pistons to the deck. Just moving the piston tops down and thinning the gasket is not changing anything, right?

If you do it the way hemichuck is doing it, you reduce the crevice volume.

If you do it the way 72 wants to, you increase the crevice volume.

Crevice volume is as important as squish. Possibly more so.