Switching Caps in 8 3/4 Case

just going out on a limb here, and pure speculation. but I would assume a cap from the same series case (741, 742, 489) and if posable around the same casting / assembly date would increase the chances of a good match.

my thinking is parts made around the same time should have about the same tolerances in construction, and the same group of machinists would have machined the parts. (I know it is a long shot and most likely not necessary.)


all that being said, I think @Oldmanmopar laid out a winning strategy for you.