My personal preference is Valvoline. I have used it for over 200,000 miles in my '92 GMC 350 V-8 that I run HARD all the time, never any bearing failure or oil related problem. Every time I drive that truck I turn it 5000 RPM regularly. It is in my '54 GMC as well, I use 30 weight in everything, I don't like multiple viscosity oils.
