Get the NV out of a Durango / Dakota or get your hands on a TKO3550 or TKO 500. Early 90's GM's used ZF's. The NV didnt come out until later 90's

If you want to go a T5 route and have some torque capacity, you will need to build a T5 hybrid and use the GM F-body V8 transmission with the rear housing and top cover from an S-10. This will not require machining the splines shorter or cutting the input bearing retainer or pilot like the standard 14 spline S-10 variations.

http://www.inliners.org/Jack/t5_page.html
http://www.inliners.org/Jack/T5tech.html

If you want better gearing than that, then find the gearset out of an Astro T5 (3.50:1 first) and make a frankenstein transmission.

The problems we face today can not be addressed at the same level of intelligence we were at when we created them - Albert Einstein Or with the same level of $ - Me