SVS did a stock bottom-end car with Stryker heads, Motec, etc and it made 600 rwhp. Neither of those 2 mods are cheap, though. My car has a 510 stroker with ported stock heads, custom cam, headers, exhaust, etc, etc. and it makes 600 rwhp and 615 rwtq on plain old 91 octane. I think there is...