The issue is the mounting location of the starter. From what I've read, the bolts holes and mounting are different on FWD vehicles than RWD vehicles and so there is an alignment issue when trying to get the two to mate.
I would think they should just match up since a lot of the FWD vehicles share their engines in RWD vehicles, but I guess that starter hole just messes things up.
This is quite a bit of work, and I have done it, kinda. I didn't use the complete turbo 3.1, I built my own hybrid, using an S-10 block, and a genIII 660 top end (3100), and used a larger turbo. The TGP uses a Garret T-25, I used a Garret T-3.
I had to make my own headers, and crossover pipe, down pipe, etc. Also with my set-up my grandfather made a custom crank trigger for the ignition system, for the DIS ignition. A distributer will not clear the intake.
The RWD starter location will be difficult to drill, since the "ear" on that side of the engine has a different shape to clear the FWD auto tranny, and will require a filler piece made and for best results welded to the block, to provide a flat surface to mount the starter to.
Since the intake will need to be turned around your best bet would be to use the RWD water pump, and front cover, there is still a slight machining operation needed.
Hehe i just blew up one of those engines, i own a 95 Grand Prix,... a tip of advice, my engine held a 100hp wet shot of nitrous perfectly, until the day that fuel puddled in the manifold, ignited, launched my cone filter off and made it into a cemi circle, and rocketed my valves out of the retainers and into the cylinder, then rammed em back and broke on the return stroke :doh: