Upgrading stock 1971 318 heads

Treblig said
Should be either .060" or .100" down in the hole at TDC.

treblig

Finally finshed Chamber Volume 302 heads are 64CC and my pistons are 0.100 in the hole. What would my compression be shaving 0.40 off the heads using 0.40 fel pro head gasket hoping to get at least 9:1