I played around with the Wallace cranking compression calculator.

It seems "highly unlikely" the motor is 10:1cr with the 484 cam, cranking 240+ psi...... Or the gauge is wrong(or maybe a little of both).

A 10:1 446 with the 484 cam installed at 104 should pump 156psi at zero feet elevation.
Assuming the duration is actually "284", and a 104 c/l, the intake closing point is 66abtc.

Changing that number to "0", only moves the needle to 212psi.
Changing the cr to 11:1 with the closing point still at "0" shows 240psi.

Assuming the cam is installed correctly;
14:1cr shows 237psi
14.5:1cr shows 248psi

I also plugged in the numbers from one of the FAST motors that pumped high, and it showed 240psi.

At this point, the gauge is still suspect in my mind.