Try testing it warm with the primary gauge pressure set at 80 and then divide your reading into each other, if it reads 78 on the low side and you divide 80 into that it equals 2.5%, correct
If you set the pressure at 100 Lbs. even and then read the low side it will read the percent leakage with no math, 100/98=2.0 %
Street motors that test from 3 % to 25 % aren't bad
If it leaks worst than 25 % then you have to decide to fix it or drive it until you can't stand the oil consumption and poor performance