[BRENT in 10-uh-C]

Thanks Mike. I am not sure if all figures are applicable, ...and I really do not have the time to study them for validity at the moment but they add a dimension that I do want to explore when more time is available. I will say that it has been my experience that metal will stretch much easier than compress given the same amount of pressure in either direction. Maybe this is appearance alone but I find metal will usually re-arrange its' shape instead of compressing.

One thought/question about what Mike is suggesting is regarding the compressing of the upper chord. To bend something, doesn't a fulcrum need to be added to the equation? If so, wouldn't the top rail be the fulcrum? If so, it would become the strongest point so, I doubt much compression would be seen as a permanent set.

I have included some pictures of a Roadster pick-up frame below that had endured a hard life up until the time for restoration. I know this as fact because the owner's grandfather used it in his brick masonry business for many years hauling brick and mortar to the jobsite. This frame was sagging in several areas all exceeding .250" below a horizontal plane. The heat marks pretty much show the areas where heat & water were applied and to what part of the metal was moved (shrunk) to bring it into proper alignment.