....

To me for a hot street strip engine would be around 1.2-1.3 hp per cid which would put peak power around 6000-6500 rpm, so 323 would be 390-420 hp. If you want more power than that or don't want to gear and stall it properly i'd really think about going bigger.

Know it's not a 318 but Richard Holdener just did a 460 hp 327 with a really good powerband