I run Brad Penn 15-40 wt. in all my engines. I use it for breakin period also. I use all the required assembly lube, and cam breakin lube that the cam makers spec to warranty their cams.
I've got 30 some qts. of old Valavoline 20-50 Racing Oil I bought NOS in the old cardboard qt. cans not long ago. I'll probably start using it also when I run low on Brad Penn.