1974 Duster wheels & tire size

So I have a 74 Duster that came with slant 6. Small 5x4 bolt pattern. I now have a 8 1/4 rear end from a B body. The rear end is 3 inches wider than the stock rear end. That means 1.5 inches on each side wider on the rear. Can someone with a similar setup give me some wheel advise?
Thank you!