Adding an OE electrical oil pressure gauge to a 71-76 A-body cluster?

Kendog 170 said

Put a T in your oil port, run a pressure gauge and new gauge side by side.Test them both outside the car. Maybe you can add readings on new gauge.

Click to expand...

Great idea. I would want to validate what those marks on the gauge mean. Assuming they are for 0 20 40 60 80 but something like this you'd want to be sure of. You could also use a meter match to correct any inaccuracy of the gauge.