The 261 we built for John's 1 ton pickup about a year ago over at Stovebolt Headquarters had about 60 PSI oil pressure on a cold start, using 15W-40 oil. I think that would qualify as "full pressure"! Of course, it dropped a little after warmup. We intentionally built that one with some pretty close tolerances, including reconditioning all the connecting rods on my Sunnen hone. Right now I'm working on a buildup routine that should produce a spray-oiler 216 with about 40 PSI oil pressure at hot cruise RPM.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!