Reply to "Call for help 1 hour North of the SanFrancisco Bay Area (Santa Rosa)"

Mike do you know what camshaft you are running?
Flat tappet or roller?
You said you liked Joe Gibbs or Driven motor oil, but I do not understand your reluctance to use synthetic.
The Driven website has lots of information about oil, viscosity, ZDDP etc. For example this page..
http://www.drivenracingoil.com...er/guides/viscosity/
"Choosing a motor oil with a higher base oil viscosity index provides the benefit of improved flow when it is cold while maintaining oil film thickness at high temperatures. Conventional mineral base oils have a viscosity index in the range of 100, while synthetic base oils typically have a viscosity index in the range of 150."
"If you are running a conventional 20W-50, just by changing to an mPAO based 10W-40, you can reduce start-up wear without sacrificing high temperature durability or oil pressure."
Give Driven a call and maybe call Royal Purple and a few others. They will be able to inform you how oil has improved or changed.