Go to a body shop and have them take measurements on a frame machine. But then again it would probably be off anyways because its an 89 fox....Especially because its a convertible.
I've done crap wrong in life and sometimes the answer is time consuming and or costly. Some lessons have no easy fix some do.
Woman has a bad back.....Then she gets a breast implant and it gets worse. Do we toss her more aspirin and send her to a chiropractor? Sure why not lol