well, the AWD part is easy- get a transfer case out of an AWD Astro and swap it in. you'll need to find a way to lock the front differential in all the time, but that should be fairly easy by hooking up the vacuum line that activates it to the intake manifold.
the V8 swap is a little more involved- but probably easier than putting a turbo on the V6.
the trans will bolt right up to a 350, but a custom oil pan is needed to clear the 4X4 stuff. special motor mounts are also needed, as well as exhaust stuff. you can buy kits that come with an oil pan, motor mounts, and headers from places like Summit and Jegs.
everything else off the 4.3 bolts to the V8- with a V8 ecm and throttle body, the fuel injection setup can even be retained- everything literally plugs right in.
i did this in a 1988 4wd S10 that i put a TBI 350 out of a 1992 Caprice cop car in it. i made my own motor mounts, oil pan, and exhaust crossover pipe.
it looked like it was factory installed- i was proud..
that little thing was a beast- but i couldn't get a title for it, so i took everything out and junked the truck. i'll do another one someday when i can find another solid $100 body.
