hi guys, well the crusin season is almost over here, so time to go to work. have taken my g heads to the machine shop to get worked. anyone have any experience as to size intake valves can be squeeked into these heads, also because with composition head gasket use, isnt a fair amount of compression lost, and if so ,should they be cut (what amount). while i am in the question mode. are y-block zero deck height blocks?appreciate any and all advice.putting these on my 292 plus 40 over 6 deuce 32 3 window cpe. thanks to all