The repo rear dropoffs are little short. Not just the ones that I bought as it turns out. So the best time to install them is after the quarters are installed. In my case I had to put the car on a rotisserie to fit them properly.
To weld thme in place I used a spotwelder that I originally bought to put the Jaguar E-Type together. They turned out great yielding factory looking welds. And best of all, all I had to do was sand them and they were ready for primer.
Torque boxes were only installed on convertibles, high performance cars and Hemi cars. The original ones that were on the car had rusted away. Resto Rick sells the really nice repo ones, but they are costly ($500). Rick does supply them with some pictures of originals so that you have a guide to install them as sloppy as the factory did it....
RIGHT FRONT: I started by epoxy priming the area that would be covered when they were installed and on the back side of the torque boxes. I printed one of Rick's reference pictures and hung it by the torque box to get the alignment right.
LEFT FRONT: In the last picture you can see my welds on the left front torque box. The factory was often much worse looking then that. I think I did OK.
RIGHT REAR: If this car had a high performance rear end there would have been a reinforcement plate welded to where the leafspring mounting brackets bolt in.
Again I attempted to replicate the crappy feactory welds here.
LEFT REAR: The welds on this side came out a little nicer than you would typically see.
After the torque boxes were welded in, I cleaned up the welds by sandblasting them. I did not want the primer and paint to fall off them in the future.