Depends on the cam. A mild bowl blend and 3 angle valve job goes a long way. Are these the Gm swirl port heads? Thats about the era they were from. If so, they are worthless. If its a normal looking port, like a 993, or 186 or something, then that power is achiveable. Just did a 327 resto engine for a 65 Corvette, that was a solid lifter engine, absolutely stick 461 camel backs, with 1.94/1.5 valves, a normal 30-45-60 valve job, and VERY minimal blending under the seat, with a very mild solid cam, he wanted the solid cam, stock rockers, and the only thing added was a Torker 2, because he had it, a new 650 QF vacc carb, and a set of cheap 1 5/8 headers, good machining, balancing, etc, it made 365hp and 385 ft/lbs. THe cam was about quivilent to a mid 220's at .o5o hydraulic, had .465 gross lift, before the lash, so the cam was by no means radical, You can barely hear a lope.
Frank
Advanced Performance
www.get-ap.com