A buddy of mine has a really nice '71 Deluxe Sunroof bus that has a
horrible transmission whine...  I have a couple of good used '78
transmissions

My question:  are the two transmissions interchangeable?  Would there be
any advantage to using the later tranny (5.375 final drive ration) over
the stock tranny (4.857 final drive ratio)..?

The '71 has a stock dual port 1600 in it now, but that may be changed
out this summer for a mild 1776...

            TIA

        JonR