Thanks for the link Joe.
SFHF, the Astro Van / Bravada AWD T-case is stronger than the part-time 4x4 T-cases. It is also the same T-case that is behind the Syclone and Typhoon trucks. So it will handle a stock LS1. A built LS2 or LS6 would break it. What T-case fits the 4l60e that you have is unknown to me, however, I would bet the T-case you have would fit.
The ZR2 has the 8.5" axles. There is a site on the interweb somewhere about swapping parts from the ZR2 onto a standard S-10. I found it once about 6 months ago by accident. You may want to try a google search. (Or Joe may have a link) There are also higher quality aftermarket 7.6" gear sets as well.
Scott
