I have heard that the GTUs's drivetrain is the TII one.... is this true? I doubt it.. anyways...
I am thinking about finding a rear axle from a GTU's... with the 4.3 gears, and LSD.
It's probably easier to swap in the whole axle than installing the gears and LSD in my carrier.
Assuming it's not the TII drivetrain... it should mate with my driveshaft, correct?? (I have the 5 bolt, 4 piston discs on the rear...no LSD..)

One more question- can you get a diferent speedo drive gear or something form the dealerhip?? How do you correct the speedo for the gears? I am assuming the GTUs doesn't have an incorrect speedo...
I'm an engine guy.... not yet too intimately famililar with the rear end yet! (Of the car... you homo!)

 

I posted this in another thread so you may have seen it already, but it should answer your question.

Oh, and good luck finding somebody that is parting out the rarest RX-7.

What's wrong with the 4.10 gears?

 

All the n/a's had a 7" ring gear, GTUs included. TII has an 8" ring gear. There are NOT interchangable. You can get 4.3 gears for a TII diff from www.rx7.com, which are sourced form the Japanese market Infini III, which had the TII rear with the 4.3 gears.