Also check for a restricted exhaust. If you have access to a delay-flash timing light, check for correct ignition timing- - - -initial, centrifugal, and vacuum. Total advance at light-throttle cruise RPM should be in the 35-40 degree range, and it should drop to the low 30's or slightly more when pulling hard at low vacuum.
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!