Jus wondering which would be best for my 02 5.3 136,xxx miles. I don't race it everywhere but I don't drive like a grandpa either. I want the best performance and longest engine life. It doesn't have cats so no worry's with the zinc/phos. Content it has had m1 hm 5w30 in it since 78,xxx jus wondering if that is my best choice. Thanks for the help