65 dart 318/904 swap- tailshaft
Just use the later tranny as a whole. If you wish to (and your local track allows you to) use the original floor shifter,
www.imperialservices.net has an adapter cable.
The 7.25 will do OK on the street for a while. Slicks+burnouts=problems real fast. Run it till it breaks and save up for 4.10's in a 8.75.