I kinda wondered the same thing, but from what I've found F bodies (what the rear end came from) only had an 8.25 and it all measures out to match the chart. I'm pretty sure the car came with a 7.25 originally since it was a /6 auto from the factory, so I wouldn't see why they would swap sideways so to speak. I wouldn't be surprised anymore though with the stupid crap I've found out about my car. They didn't just swap the rear end, they pulled the whole rear suspension with it, so I have the rubber spring isolator boxes on the leafs and the wrong shocks with a post mount on one end and the bushing on the other.