1965 Valiant rearend options

I'm looking to upgrade my 1965 Valiant from a 7.25" rearend (with 4" lug pattern) to a 4.5" lug rearend ( 8.25" or 8.75" or bigger -- if i needed to for fitment.) I'll probably gear it down (maybe 3.90:1 or even 4.10:1).

Recommendations?