My experience is that panel trucks are relatively rigid. My 1/2-ton panel didn't twist at all (doors still opened and closed just the same with the body off) but your 1-ton is a longer, heavier cab. As long as you keep your lifting points fairly level any twisting should be negligible and will return to normal when the body is bolted back down to the frame. And if they were prone to twisting, would the factory have lifted them like this?
