frame on a 02+ requires z'in the sub frame 1.5" in turn you can also raise the trans that much with the stock trans x member since it only hangs 1.5 below the frame.
then ditch the stock spring pirches and make some new mounts..
I prefer (MY) ekstensive LCA's with flipped chevy balljoints. lets the subframe lay flat
other then that the gas tank hangs down 2 inch's below the frame rail as well.. people have raised the stock tank mount.. and others ditch em...