There is a kit available to adapt a S10 4X4 T5 to your torque tube so you could use your stock rear. Can't remember who was doing it but it was covered on the Hamb a couple of years ago and I've saw one car with it installed.
A little searching on that site could turn up the info.
Paul
Walt
The engine is pretty much stock inside. But plenty of power for the little car.
You can see a couple of pictures in my profile.
It's the most fun car I've built.
Thanks
Paul