64 Viper Dart??

Stroked 360 would get you over 400 cid and could make 500 HP with some good heads and a big cam.

That's true, but it depends what he really wants. A 500 horse stroker small block is most likely not going to be very everyday driver friendly.
If done right, a turbo 318 could produce far more than that and the pwer level could be adjustable from the dash.
I will be posting my build on this site when I finally come up with the plan and the cash.
I reccomend that the OP does a lot of reading. Here is another site to check out: http://www.theturboforums.com/smf/index.php

Lot's of good info there.:read2: Scroll down to the Mopar section.