According to TRW, 7cc dome, 5.7 rod= -.020 deck, 64cc=12.55/ 68cc=11.95/76cc=10.9......Hope that helps..........I don't think there is anyway to run those pisons with those heads and pump gas, unless you machined a dish in them.......11cc dish would get you to the 10.8-11.0 range, BUT, how thick are the tops?....MP