[Jeff Chambers]

Andy may correct me here, but some of his experience is based on the NMRA requirement that they maintain a minimum quench of 0.038". Over in FFW, we have no such requirement so we do everything we can to get the compression ratio as high as we can. My TW heads have been milled nearly .200" to 38cc chambers, with oversized valves to the point that the intake valve is actually proud (hangs below the head surface). I use a Yates-style gasket and relieve the block a little locally to clear the valve, a 0.035-0.040 head gasket and zero-deck the block. At 9000 rpm, the rod stretch is actually enough to bring the piston 0.003" or more out of the block for even greater dynamic compression.

Heads up racing baby! If you want the trick stuff, that's where you'll find it.