Oh man, my bad. I read your posh wrong. Thought you were looking for belts. I have a couple of diffs is been willing to part with. But you might want to look at what's causing your issue. If you're going thru belts and diffs, then it's an issue somewhere. I use high reving 21s in my cars for speed runs and haven't been thru a belt or diff in at least 4 years. And the cars are way up there in speed.