Redline 5w30 has virgin viscosity at 100c of 11.9cst, HTHSv of 3.7 and NOACK of 6%.
Blackstone didn't seem to realize this.
While your lead is higher than universal averages, your iron is lower.
Maybe change oil. What do GM say you should use? Isn't it M1?
That would certainly get your iron in line with the universal average.