8.75
Unless you can live with a rear at 51.25 housing width and have wheels with a bit deeper dish, that's an option.
Cut the long tube to equi-length and move the perches roughly 5/8" to pass side to center it again.
What a mess. If he doesn't fix, I'd put his stupid *** on blast. Then follow it up with a healthy small claims court lawsuit.
We had layout sheets, LONG before the internet, when doing stuff like this in the shop. One of the questions... Is the pinion centered YES ___ NO ____
If the customer didn't know, you had to get the answer. That's the difference between people that do stuff right and just do stuff.
GM guys ******* up Mopar parts since 1965 LOL