04 5.3 w/100k....mobil1 since almost new 5k.Any preventitive stuff I should do...like timing chain or oil pump.oil presssure is at 50 idle and maxed at anything over 2000 rpm,doesnt make as much noise as when it was new.The plugs looked like new...just a little larger gap.and I run drive the piss out of it and tow a trailer.