I did it on my 67 Dart. Been a while.......but IIRC,the belts came w/everything to mount. Cut out a square section ( about 2"X2") and welded in the nut in its place. The nut came w/metal already welded on it. It fit into the hole I had already cut out. Seems like the instructions give you an idea where to mount. Run over my shoulder and down to hip at attachment point. Work like driving a newer model.

Can't remember what company I bought from.