oil pressure

[FMags2@domain.elided]

I will be installing an oil pressure in my Stag shortly.  I have two good 
aftermarket oil pressure gauges in my box of gauges; one is 0-80 psi, and the 
other is 0-100 psi.  Any suggestions as to which one to install?  What I 
really need to know is what is the max oil pressure that I can expect from 
this engine starting cold?  It gets well over 100 deg here in the summer, so 
I expect that I'll be running 20W-50.  My GT6 runs about 85 psi cold with 
20-50, my Healey about 70.  The only V-8s that I'm used to are Chevy 305,350 
and they run about 50 psi from a cold start.  Any advice appreciated.
Thanks, 
Frank M.