darin where were u when we talked about that?
it has already been shown that custom ground cams combined with a good port and polish job on the heads can produce upwards of 33whp gains.
with an intake, exhaust and a good header your talking more like 45-50whp gains, now ur almost in the range of the MSP and ur still NA.
add to that a flywheel, pulley, pistons and an ecu upgrade to tighten the compression a little you are realiztically looking at 55-70whp gains when ur about done with what you can do N/A, and the ecu is important.
Id be plenty happy with 160-165whp N/A meaning like almost 200-210 at the crank, make those wrx's work for thier money when racing.
So a N/A buildup is possible and with what I listed below your talking about 2-3 grand. about the price of a stage 1 or 2 turbo kit without worries about boost problems and no waiting for boost.
hell according to corksport if u swap in the almost as weak Jspec cams,pistons and intake manifold they say you should be around the Jspec hp rating.