It's not so dangerous to put it on a lift and do it, but a jack, or a block of wood, or even jack stands is somewhat more risky.
If you do put it on a lift and run it obviously don't stick your hands or self in the way of anything moving. Also don't do anything fast, don't accelerate hard, and don't brake hard, as it can move the truck.
I think I would hold off on that method till after you check the angles and feel for loose parts by hand, if that does not reveal any possible problems, and you still have a problem, then try running it in the air.
Grigg
