I just installed some new rear spring isolators. They do not look like the factory ones. They are however GM ones. Well I put them in because the old isolators #'s were moved to this new design. Anyways. What is the proper cleanance between the fender and ground? In front I have 27 1/2 on both sides and on and on the rear I have 28 1/2 Sound about right? I forgot to measure before i put the new ones in I havent driven it yet so maybe the rear springs will settle back in. Thanks