340 Magnum Piston/Head Clearance

Well, if you use the thicker head gasket you will lose more compression than if you mill the pistons. That seemed to be a concern of yours. Perhaps you should get an accurate measurement before you make the decision? I think there should be some measuring and calculating rather than quessing from photographs. Howsabout doing a .500" down fill volume and cc'ing the heads before doin' anything?