408 horse power?

Somewhere between 250 and 500 would be my guess. Don't mean to be a smart axx but there's no way anyone can guess the hp with what little information you provided. "A nice Comp cam"?? Since there are at least 1000 nice cams from comp that's not much to go on. Was the cam degreed in? That can have a profound affect on how an engine runs. Plus that's not much to go on with the description of the heads either. Are they 273 heads that someone installed 2.02 valves in, or 340 X heads, or Edelbrock heads, or Indybrocks, or RHS??? The cam and heads are really what makes the power package so it's imperative that you provide every aspect of the build. Flow numbers (or at least a real good description, such as the casting # and ALL work done on them) of the heads is a HUGE plus.

BTW: What the heck are 30 degree valves??