I'm just going to weld a couple of gussets to the mount and a verticle spine to keep it from flexing. I also found out that part of the problem is that all the mounting holes in the bracket are oversize and the only thing holding it in one specific place is the friction caused by bolting it together. I guess if it were to rust in place, it would be OK :gag:
I'm going to weld some plate over the holes and redrill them to the right size, then mount the bracket and then tack weld it in place.
What a pain in the ass.