Did you go with Amsoil?
I should've posted sooner, but yeah, it's the real deal. The company I manage uses it exclusively in our fleet of vehicles; never an oil related failure in the 18 years I've been here and we've pushed a few of our trucks over 300,000, but you have to give credit to engine design and a routine maintenance schedule, BUT these trucks do not see an easy life.
I use Amsoil personally as well; no issues. My last Suburban was sold with 245,000 on the clock and still ran like new, but those 5.7L engines are great. I currently have a Silverado with 80,000 on the odometer and a Ram 2500 with 118,000 Amsoil in both since they were new. No issues.
IMO, they make some of the best gear oil on the market.
It is still under the Toyota vehicle maintenance plan until I roll 25k on it. I think the dealer is using Mobil 1 full synthetic and I paid/pay for the 5k 15k 25k oil and filter change . Bottom line is I am not running it past 5k without an oil and filter change ....too set in my ways to change. It was hard enough going from the 3k oil/filter change interval
