I would look for a T4 turbo like the GT42 or GT45 knock offs. They are like 300.00 shipped. The vulcun is a good canidate I believe too. Hard part would be tuning it, but since its OBD II it might not be so bad. If they can get 1096rwhp out of a 4.3 vortec, then I think you should be able to get half that out of the vulcan.