09-01-2019, 11:22 AM
(08-31-2019, 02:30 AM)1969_Mach1 Wrote: If you have the stock ignition system, leave the gap at the factory recommendation, I believe that is 0.035". I like either Autolite or NGK spark plugs.Thanks for the info! I did put in NGK after some more research and actually, made a big difference. Still think the car is running a little rich and will check on the jetting and see if rejetting will help.
I would use the stock heat range for your car, increasing the heat range will increase the chances of pinging (preignition) which is bad for any motor.
Since your plugs were carbon fouled, the motor is either running too rich or something in your ignition system is too weak, i.e. bad ignition coil, or more common the resistance in the spark plug wires is too high. Cars of this era didn't have today's powerful ignition systems and spark plug fouling was much more common where as today it is unheard of. Ignition timing too retarded will also cause a motor to run too rich.
One thing I would do is freshen the carb. Most people with Holley carbs will freshen them up once a year. Something as simple as an air bleed being plugged or partially plugged, or leaking power valve gasket will cause it to run too rich.
After you know your ignition system is okay, and the carb is in good condition and properly adjusted, if it still runs too rich, then we can look at carb rejetting.