[Excaliber]

Quench for the FE is not so much a factor of the heads as it is the specs for the piston being so low in the cylinder at TDC. As much as .030 below deck. I utilized custom pistons for my FE build which moved the piston up to zero deck height via the piston pin location, thus gaining some nice 'quench'. That allows you to run slightly higher compression ratio's and the engine is less susceptible to detonation. It's working out rather nicely for me, I've never had detonation even under a fierce load condition (low rpm, high gear, lugging the engine).