73 Dart Rear End Swap

Find a rear from a c body or other big bolt pattern car and have it narrowed, about $150 - 200 to narrow the housing. It will probably already have big bolt pattern brakes. Spend another $300 or so and buy good axles and you're done. For what they're asking these days for small bolt pattern A body rears I'd do this.

The C and E body rears are much wider. The cheapest option is to use the 65-70 B body rear in your A body. It's only about and 1 1/2 -1 3/4 inches wider on each side (the 65-67 is even slightly more narrow). They can be had whole for $100-$250.

The A body spring seats are 43 inches center to center and the B body is 44 inches. Some people move the seats in a half inch, I just pull the leaf springs sideways and the rear bolts in place.

The 73-76 A bodies also had a wider track on the front with the disc brakes and a narrower track on the rear. The B body will fix that and give you the same footprint front and back.

Also, if you want to be REALLY cheap, the A body 8 1/4 (one quarter) rear (available in bbp) is a bolt in swap and it holds up to a lot more punishment than the 7 1/4.