The timbren actually transfers the load to the axel sooner than the factory stop. That should be putting less stress on the frame. There's also a heavy steel (washer) that sits between the frame and the Timbren which supports it.
Great thread about truck campers. I just bought an SS500 from palomino that's being delivered today. I can't see going over 1400lbs fully geared up and the truck is rated to haul 1840#'s.
I did add Timbrens in lieu of the factory leaf spring stops. From what I saw, that should reduce or...