Mopar A body 8 3/4 housings

Forgive my ignorance on this subject. My brother recently bought a 75 duster and it has 7 1/4 in it. Would this rearend be right for a 75? I found a list on here that lists rearend lengths and the 52 5/8 but only lists up through 72.

Also.. what would the shipping be to St Helens Oregon.

Thanks a lot