We run SAW air bumps, and we charge them to 200psi, per SAW. It gives the truck a real nice ride, and when racing I want to know when I am really pounding the truck. At this psi with the triple bypasses, if we are bottoming the truck, we need to slow down to save the truck for the rest of the race. I would suppose if you were out at the jumps for an IP meeting I would charge them a little higher for the one time hit. I suppose it just depends on the application. Our Toyota doesn't weigh a hole lot either. We need to be 3000#s for 7s and we have brought it real close to that weight. I agree with Tigger, I would call the manufacturer of which ever bumps you are using and tell them your application and see what they say.
Later,
Jason