Question Asked: I am running a GMC inline six cylinder in my 52 Chevy. I recently had a misfire
April 02, 2013, 08:28 AM
I took it in and discovered the valves had heavy carbon deposits. Some of the valves were sticking in the valve guides. we increased the diameter of the valve guides and reworked the valve seats. I have been advised to use a 20-50 Valvoline oil which contains zinc additive. I am also using an octane booster in the fuel.