The S10 T5, which is basicly what the astro trans is, with a diffrent tailshaft/ shifter. won't hold up behind much more than a mild 350, and any hard shifts, are going to scatter parts on the pavement.. your better off with a 700 R4 automatic, beefed up with a trans cooler, and some upgraded parts... aside from that, you might be able to use a V8 Mustang T5, with the S10 input shaft, and Astro tailshaft. it will have to be modded to work, but I know that has been done