[SabreKhan]

I don't know for sure, but I would bet you wouldn't want turbo internals in your non-turbo engine. Turbo internals are designed for high-pressure applications (high air flow and high fuel flow), so without the increase in the air/fuel mixture I'd be willing to bet the STi internals will actually make a non-turbo engine weaker. The compression ratio ratio can't be favorable (yes, I typed "ratio" twice on purpose).

If you want to go turbo, it would be easier by far (and probably cheaper) just to do a motor swap. You can just ship your old one to me, and I'll install it in my dune buggy.