Switching from Valvoline VR1 to Brad Penn: suggestions?

I'm planning on changing the oil in my street/strip 440 (flat tappet) engine in a few weeks and I'm thinking about going with the Brad Penn 15/40W partial synthetic oil. I've never used any partial synthetic oils (previously have used VR1)...anything I should know before making the switch?

I use 20/50 Brad Penn with a bottle of Hughes Engine additives

You will love it ,been using it in my race motors with flat tappet cams on alcohol ,without additives

Go to a full synthetic such a Royal Purple racing oil - 10W40. You won't need an additive ( zinc built in ). You will be able to run a lower viscosity ( reads less friction loss ) with the same protection and improved heat degradation capabilities.

Valvoline NFS already has loads of zinc and phosporous. That is my choice.

Leon