870c and 91 diff centres?

[Bormac]

Here's one for some of you guys with some better than average Yoke knowledge. I have been rebuilding my Yoke diffs and counted 35 teeth on each pulley. The pulleys are identical with a guard which glues to the side to keep the belt on. Its on my 91 car but I think it doesnt have the fine pitch of which i hear was a bit of a let down. I'd like to run the car with a mild mod motor and am wondering what your opinions should be as to which pulleys are best for the application? The funny thing is, I got out one of my 501X pulleys and would you believe it fits the diff? The 501 pulley i had was the 37 teeth but Im sure they make a 35 tooth gear for the overdrive on the front. Anyone ever thought of looking into this?
Also when i went to replace the standard diff balls with 3mm ceramics I found the genuine balls to be a bit larger. Are these an imperial size diff ball I wonder??
On a side note,if anyone has a spare front and rear belt I would be interested even only to track down some similar stock from a local belt compay here in Australia. Cheers-Jason.

[Mr. ED]

I've been playing around with different pulleys: of the trf, TA05, ABC, HPI,... but didn't find anything that 100% works: because of the thickness being off with different balls etc.
I do have front bulkheads in 2 parts which I could space for it to work but then I also need to find the rears and make a custom chassis, and... too much work.
If you do find a way, be sure to let me know. To get the front in overdrive is exactly what I want, and a crazy experiment with a one-way in the rear to go with it.