If you like powerful, streetable NA engines, you have 3 options:
1) Domestic V8 (Chev 350, Ford 351)
2) Honda VTEC (Honda S2000)
3) SR20VE (not much info about this engine stateside)
As a side note, what's up with the FUD over forced induction? "Turbos scare me. I'd rather run a 20:1 hi-comp KA. It's much safer, way cheaper, soooo much easier AND I won't be jumping on the bandwagon with the rest of you idiots! Instant 300whp!"
Todd
90 Coupe NA
93 Coupe T
PS Read about Andrew's hi-comp engine build for some heartbreaking shit:
http://www.mountainracer.com