I re-checked my calculations. I am right a 10.13 with a 70 cc head and no quench (.080). That is with a .027 thick gasket. If I mill .050 off the head the compression will go up 1 point. I believe that is too much for a iron head on pump gas. I read the info Polyspheric posted..... good info. I will buy a head gasket and see what I can come up with. Playing with the numbers I need roughly 10-11 cc less than I have if I mill the head to be closed chambered and have .033-.035" quench.
Where did you think you were? Iron heads, 9.5 comp is the safe rule of thumb. If it were me , id go for quench, mill .030/.040 and then deshroud the head. I haven't done any of the math except the quench, trusting you on the comp figure. But quench is always better if its in range and you can figure out how to get it.
