J Wondering,Dont take a chance on something that GM isnt recommending for your truck.If they know you have used something else then what your suppose to use they would tell you right out that you didnt go by there spec's.That would immediatly void your warrenty.If you stay with what they recommend they have to honor your warrenty if something goes.Beleive me when it comes to the warrenty they'll stick tight to the book.After warrenty then your on your own,then it dosnt matter.Hammer [img]smile.gif[/img] [img]smile.gif[/img]