Hotrod cams on a stovebolt are like lipstick on a pig. The only thing a stovebolt six has going for it is torque, and too much duration destroys that. Extra lift? Maybe on the exhaust. The intake valve gets close enough to the piston already, even with a stock cam. If you want to make the engine idle rough and make people think it's something it's not, go for it!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!