Anyone want to swap diffs?

[beardydave]

Mine has bolt-on shafts, does that mean that it might not be the ratio it was sold as? I think it's a 7.5" diff, but I don't quite understand all the different codes on Sierra diffs.

My gearbox is from a 328i e36, I calculated the speeds on an online calculator based on 15" wheels and a 7k rpm limit. I could have got it wrong though.

I was originally going with a bmw lsd modified to a 2.91 ratio I picked up, but it was too big.