100 psi oil pressure on start-up

[cycleguy55]

10W40 should drop your idle pressure, both hot and cold, but in my part of the world I can't find a listing for 10W40 VR1. 10W30 is listed, and that would probably work just fine, as long as you can maintain 10 PSI / 1,000 RPM (e.g. 30 PSI @ 3,000 RPM, 40 PSI @ 4,000 RPM) and I can't see any reason why not, especially if you now have 70 PSI @ 1,000 RPM with a hot engine.

Personally I would go full synthetic, especially if you're running a roller cam. There are many leery of synthetic, especially with flat tappet cam & lifters - where higher levels of ZDDP are recommended to prevent wiping out lobes.