Sweet! Thanks Jerry! Looks like I can confirm it: all the hondamatic heads are -392 heads but with no markings. The intakes are the same size and same with the exhaust. Both the exhaust pipes and the intake rubbers are different and restrict the engine quite a bit. The cylinders are also the same, as are the rods, so if you come across one in parts...they're great for low K motor bits! The bits that are different are the crank, cam and pistons, but the rest (rods, pins, clips, towers, etc...) are all the same.
