Swap to a 2.4 block with your head.
You can also stroke the 2.4. I've heard of people running ~2.7 liters of displacement with that kinda setup. Raise the compression quite a bit and you could have a nasty non turbo car. Only problem is the weight of the car. Get that down and you could have some fun.

hahnracecraft.com does turbo kits for the non turbos.