I was hoping someone could help shed some light on this. I answered an add on Craigslist saying he was parting out an 88 convertible. I was going to purchase the rearend out of it because he stated that it had an 8.8 inch rearend. When I went to pick it up, he was in the process of removing it and after inspecting the rearend I told the guy that I was certain that it was not an 8.8 inch rearend. I have an 83 GT that I wanted to swap the 8.8 rear into and I started to notice that everything about this rearend looked like mine. Upon looking at the diff cover I discovered that it was indeed a 7.5. When I told the guy he said that the title to the car stated it was a factory V8 car and claimed it should be 8.8 because it had posi. My question to everyone is this, if the car was a factory 5.0 car, would it come with the 8.8 or could it have been 7.5? Also, it did not have quad shocks on it, do all 8.8 rears have the quad shocks? The guy got mad when I told him all this and I left. I am 99.9% positive it was 7.5. Any additional info anyone could share would be greatly appreciated. Thanks!!