The easiest solution, like evan said, is use a Transaxle - I know the Porsche G50's are supposedly good to a thousand HP, but I don't konw if they will hold up in a heavy vehicle, high torque situation. I do know they do nicely in the Ultima's, with a 700HP one recently taking away the 0-100-0 title from the Veyron.
A friends father was building something similar, the last time I saw him. In his case, it was a Tunnel Rammed 600HP 396 in a mid engine location in a 1970 C-10 pickup. I think he did it using a short length auto and a high misalignment driveshaft using CV joints. But the last time I saw him was around 2001, so my memory may be a bit fuzzy.
Honestly, I thought something similar would be a nifty project, a S-10 pickup with a 383 stroker motor and a G50 transaxle. the cool part would be the hard cover on the bed, using the old drive tunnel to duct air to the motor from the grill. Add on a a fiberglass hood to reduce the front weight even further. Should be able to wheel stand nicely.
EGO partum , proinde EGO sum