Gonna be tough to make 450 hp n/a without more compression ratio. I have an about 450 hp 340+.030, but I wouldn't call it streetable. Never dynoed, but the various calculators put it at somewhere between 430-465 hp. 12.2:1 forged pistons, .585/275°@.050 solid cam, 1.5 rockers, decently ported T/A heads w/ port matched single plane intake, highly modified 750 Holley DP carb, 1-7/8" headers, side kickout Moroso pan and crank scraper. Ran 11.0's at 120 in a '70 'Cuda. I built this in the 'early '80s, so better technology may make a bit more power, but CR is king.