Ever wonder what the heck Mappe's stamp is supposed to be. It kind of looks like 2 birds humping while looking at the moon. The fx400s were the early ones. Id call that a mid term case being that it has the updated case bearings and longer crank snout. Might want to clean up that head to. She's got a nasty overhang there under the valve seats.
Look at your cylinder head pic. In the two intake valve pockets there is a shiney area the shape of a thumbnail type moon. That is the overhang he is refering to.
LOL I was taslking about the finish machining of the intake seats. See how there is a ledge there. Its a rough spot that affects flow . I have heard these are because the intake runner castings on some heads didnt line up witht he seat holes. Thats where you get the ledges from. You can leave them in but its free power to clean and smooth those things up.
For a second there I though he was refering to the humping birds comment. Ya beat me to it Ken
Ya beat me to it Ken
