I use Greased Lightening or Lucas additives in my GMC 305 V6. Truth is liked mentioned....best oils you can run are those already formulated with the right amount of zinc. I will be running Joe Gibbs Straight 30 in my 292 when I run it. But for my 305 v6 I run napa synthetic 10w-30 with greased lightening or Lucas. Been fine.
Last edited by TJ's Chevy; 02/17/17 03:55 PM.
