Stupid Question

There is really no correlation between cranking compression as read by your guage, and the actual static compression built in to your engine. In order to get the actual static C.R., you need to know things like the exact c.c. measurements of the combustion chambers in your heads, piston design, depth of the piston in the bore, head gasket size and thickness, etc. 408 and John are probably pretty close on your cylinder pressures.