6 speed swap project

[CrankyOldMan]

Originally Posted by Bluevitz-rs

You might just need to swap the diff from the 5 speed and you'll be all set as the axles fit it already. C60 uses an 8 bolt diff, so if the C50 has the same thing, all you should need to do is change the ring gear.

Sadly, there are two different sized 8-bolt differentials. I learned that the hard way when I bought the wrong Quaife LSD and had to pay a 25% restock fee. The larger displacement engines use an 8-bolt diff with a different diameter shoulder for the final drive ring gear and a different spline count in the spider gears. It might be possible to swap spider gears (I could check using the spare diffs from my gearbox teardown) but it's easier to just find an OEM axle that works.

From what I can see online, the spline counts from the xD are correct. Not sure about diameter and length of the insert stub, or if it's the same diameter, but I'd be willing to bet that they will work.