I'd suggest tapping into the side of the block temporarily with a gauge you know to be accurate, possibly one with a 0-50 PSI range or so. Factory original gauges have a tendency to be extremely inaccurate at times. Since "idiot light" switches had a turn-on pressure of 7 PSI, a lot of engines without a gauge that had a pretty severe pressure drop at idle never let it be known. As long as the pressure comes up off-idle, you probably don't have a problem.
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!
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