Frame stress points

[K30_dump]

Hello all,

In building my K30 dump, I am using a frame from an '84 K30 cab-and-chassis (former ambulance). The frame is perfect with the exception of some moderate rust pitting around the leaf spring crossmember/front hangers for the rear springs. Most frame horror stories seem to include breaking just behind the cab (my other K30 frame was broken right over the rear axle where the channel narrows). Is this a high stress point, or nothing to worry about?

I have considered fish plating it, but I'm really not comfortable welding to the frame and I fear that bolting a plate in may lead to more rust once water gets behind the plate. Thoughts?

Thanks,

Joe