Reaching deep but I'm 90% sure nothing is on the cylinders/heads and it's on the cases. Could have sworn on the right side near the breather on the top rear right of the case behind the vertical head. Hopefully someone can get you a more solid answer but I have pictures at home somewhere I'll take a look for you tonight. We are talking about bevel heads right?
If you give me the engine number I should be able to find out what VIN it came from and determine it that way. Otherwise, I think the 750ss only came as a 5spd and never a 6spd. So if the gearbox is in it you can verify that way. oh, too late... what he said^