Oil pressure seems high

Ive only had my Dart for a few days so Im still in the process of going thru it.
Its got one of those triple gauges with oil, temp, volt made by autogage. Doesnt seem to be to good of quality, but it is connected properly.
Anyways, 340 motor, X heads, rebuilt to stock specs with about 3k miles. Im not sure of clearances yet. Was going to pull it this winter to check out the internals. Gauge reads 75-80 at startup. Remains in the 60-65 range at op temp idling. Seems high right?
Is the best thing to pop off the sending unit and check with a tester? Or should I check something else first? Thnx