Is 20W-50 too heavy for my 340?

I have some 20W-50 VR1 “High Zinc” in my shop and am planning an oil change. Is this too heavy?

Information:

Flat tappet 340
High compression 12:1?
Older engine oil pressure was on the lower side if I recall correctly maybe 30 psi but don’t recall what oil was used.
Lives in Phoenix and it’s getting HOT!

If not what do you recommend?

Thank you!
It's fine. Nothing wrong with a little extra viscosity.