I have a friend, who is a know it all, and he says ( I need to win this disscussion, case of beer is at stake, and he's a lurker on this board ), that the upper gearbox, gear ratio is mated to the lower case gear ratio ( prop casing ) my understanding is that the gear ratio is in the lower prop casing and one could use a , let's say a upper gear case from let's say a 275, 4 banger and put it on a 280 v-8 prop casing and not have to worry about the upper gearing, I hope I'm right?
