Dad is building a 10.5:1 408ci roller motor for his Coupe and we're having some serious reservations about the 8.25 that is in the car now. The trans is a 727 and the car will be street driven mostly with 295 radials in the back; it will occasionally see slicks for track use. The motor will be pushing 500HP and the budget for the axle is $1,000 give or take. So far our options seem to be:

8.75: The original idea was to grab one out of a 66-70 B body as the flange to flange width is 55" vs the 54.34" of the original axle. Problem is finding one of these isn't very easy to do anymore.

9.25: I did manage to find one out of an early 80's Ram with a 5x4.5 bolt pattern, SG and 3.23 gear. All it would need is new brakes, perches, and to be cut down. Junkyard wants $150 for it.

D60: We're not opposed to it, but don't know what to look at for one that will require the least amount work to get it to fit. I assume it would need everything the above 9.25 would need with the addition of axles to change to the bolt pattern.

Thoughts? Thanks guys..