Re: t150/t170 swap questions
Well, I just swapped in a t176 into a '80CJ7. Not completely sure if this will help, since my factory tranny was a SR-4. First of all, you're right, keep the driveshafts with the respective trannys. I had better luck (working by myself) installing the tranny without the tcase, then attaching the tcase before raising it into final position. The off-center tcase wants to twist the tranny & it's a bear to line up.
The biggest problem was the skid plate - the mounting holes on the frame from the SR-4 didn't line up. You can either drill new holes in the skidplate or (like I did) install new captive nuts in the frame (requires holes cut into boxed frame to weld in nuts - the holes are afterward patched over).
Every thing else bolted up.
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