I'm bagging my new 52 chevy and am going the wo link with torqu tube like a few other hambers have (no negative 2 link comments, I'm not looking for debate) but I am running the mounts off the side of the top hat frame. The frame's solid, but instead of welding to the side, which is a kinda thin, I was going to weld a foot long 1/4 inch plate onto the frame and then weld the mounts to that to spread any forces out. Good idea or just overkill? It would probably be easier this way, also, cause I could bench weld the mounts and weld them to the plate, which would be pretty easy to weld to the frame .(the body is staying put, so this is all under the car welding). I wouldn't be adding any stresses would I?
Yes, a doubler plate is a very good idea. The side wall of the frame is not real thick and the forces can cause the metal to crack and rip out. Not a good thing when it is holding your rearend in place. I think 1/4 inch is overkill, 3/16 is plenty. Welding the brackets on the bench is a good plan as well, easier to weld and make sure you get strong welds.
i would plate it . the stronger the better and the plate won't hurt . i have a 4-link and used plate on top and bottom.