4" to 4.5" rear wheel bolt conversion on a '64 Valiant?

J Glenn said
(I'll get flamed for this, but...)

I used a 1965 Ford Mustang 8" rear-end on my 1965 valiant. It has a 4.5" bolt pattern, stronger rear-end, more gearing options. The axle width and hanger locations match the early a-body 7&1/4 mopar rear for the A-bodies almost EXACTLY. That's the good. The bad: the spring hangers were 3" not 2.5" (apparently some of those mustangs had 2.5" but the one I got had 3"). The mopar 7&1/4 had 2.5" hanger. So I had to deal with that. The axle TUBE was 3" on the 7&1/4 mopar and 2.5" on the Ford. I had to deal with that. Also, the pinion-snubber setup is different (I currently do not have a pinion snubber!). Also, drive axle u-joint is not the same, but you can get the correct u-joint for like $17.

Nothing to get flamed for- you use what works. I honestly forgot about the Mustang/Falcon/Maverick rears- just don't mistakenly get a 4 bolt... then you're really SOL. The late 7 1/4 is probably easier to locate and MUCH cheaper, as long as you're not pushing a lot of power through it. 8 1/4 or the Ford rear would be second choice, just because 8 1/4 s are starting to go up in price as a result of the ridiculous prices some people are asking for 8 3/4s.
OP- you've got a few reasonable choices here- now it's just a matter of what you can find, and how much $$ you feel like spending!