As some of you know I've been working on a roots blower setup for my car. Everything I have fabbed up is working flawlessly now but I've come to the conclusion that it just aint gonna run on the stock compression ratio. I've gotta get it lower. I know the easiest way would be to put thicker head gaskets on but that will open up the squish area quite a bit and make the detonation problem even worse probably. My only option other than that (with the exception of pulling the motor) is to hog out the combustion chambers. I was just wondering if anybody knows how much someone like Loyd Elliot hogs the combustion chambers out when they unshroud the valves?? I was using the CR calculator at the top of the page and according to it I need to hog them out to about 73 cc to get it down to an 8.5:1. I know some aftermarket heads are 76cc, I'm just curious if I have enough material there to hog it out that much. Any of you guys that have had head work know what yer cc's were??