Does anyone know how much can be taken off a GMC 302 head safely. The GMC engine manual says limit is .020 inches.
Another area where I might be able to improve what I have is lubrication. I have always run Valvoline 50 weight oil. It has done the job, but it is heavy and thick. I might be able to run a lighter oil and reduce pumping losses and still protect my engine. Any experience out there with lighter oils in a GMC 302?
