If you are worried about being ok run a mechanical gauge tee in and compare. The factory gauges are all over the place. On my 69 Charger straight up is 40 psi. Is it accurate I do not know. So if straight up is 40 divide the 0 to 40 and see what each should rear. Example 3 notches between 0 and straight up would be 10 psi per notch.