Re: What did you do for your GMC today?
Some of us are using Shell Rotella oil, looking for it that has zinc in it, helps protect the flat tappets. Most of the new oils are designed for newer motors with cat converters and roller tappets, so all the good stuff for older motors is not there any more.
Since then in some other cars I started using a Lucas Hot Rod classic oil from Summit racing, has a high zinc content labeled on container, designed for flat tappets motors.
|