Figuring out Dynamic compression

I've got a 300hp crate 360 magnum in a 91 short bed 4x4 truck.
Im curious as to what the dynamic compression ratio is on this engine.
I live at 4000 feet above sea level, and when doing a compression test with the engine at operating temp and the carb wide open I get 150psi across the board on every cylinder.
In told this number would be a little higher at sea level, how much higher I don't know, but doesn't it help to determine what the dynamic compression ratio is by determining cranking compression psi?