For a low cost G motor, the old MR2 Turbo engine was actually 4 cylinder off the 2JZ Turbo (actually, the 4 cyl came first). We ran one on stock cams, stock head, stock manifolds, and modified stock turbo. Its best was 186 in a mod-roadster. The engine is leaned to the right, and the V6 tacoma bell housing bolts on, making trans adapting easy to line up. Its an iron block with a forged crank and rods. These were built to be a turbo motor from the get-go, with the turbo oil feeds, piston oilers, block ribbing...already in place. Kinda heavy, though, and handles the same size clutch as the trucks.
If you can find a Celica All-Trac ECU, I can post a pic of which two pins to jumper on the back of the circuit board. That trick enables an 8000rpm rev limit, no speed signal needed, and built in program for 18+ boost with Supra Twin-Turbo injectors. This does NOT work on an MR2 ecu because they were not used for World Rally.
You can spend more money on it and be as fast as the Aase brothers MR2, if your ship ever comes in.
Still waiting on mine...
JimL