I'm sure this has been covered before but I can't find it.

I have a universal T56 with the mechanical speedo. I need
to re-calibrate for new rear gears. The parts guys are not
going to be able to deal with the T56.

If the T56 uses the same speedo gear as the T5 in the tail
housing it should be easy but I don't know if this is the case.
Does anyone know?

Does anyone know what replacement gears, teeth count,
I would need for a 4:10 rear gear?

Any tech articles out there that would help?

Thanks,
Jim

 

Yep, same thing as T5 parts, a GM dealer with half a brain could help you, but I ran in to many that just "don't have the time"