I have a sb Chevy 355 in my '56 Chevy p/u and I'm having a problem with hesitation on accelerations and a rough idle. The engine: 350 chevy 030 over, vortec heads (new), mild cam, HEI ignition (new), splitfire plugs (seem in good shape), fuel 91 oct w/2 pints of cleaner/drier in it, flattop pistons, edelbrock 600cfm carb (new). Vacum 21lbs and solid as a rock, accelerator pump squirtin' real well, plugs clean, cap/rotor new, fresh gas, This engine has been real solid although I recently have been putting the miles on it as the other car is in the body shop. Idle is rough and hesitates and knocks on acceleration, runs better when warmed up. Cruisin' at 75mph no problems whatsoever. I can't figure this one out, this truck would smoke 'em on take off, now I'm afraid of hondas. One possible clue the dash voltage guage has been reading slightly lower than usual (44 y/o guage though). The voltage into the hei is measured at 16.5 volts. Alternator puttin out around 16.5V.
Any help or suggestions would be greatly appreciated.