I have two A's with Weber 32/36 carbs. Both cars are using the Holley low pressure regulators. The Zipper is running 4 PSI and the CCPU is 2-1/2 PSI. Correct pressure should be no more that 3 PSI Cannot adjust the Zipper to less than 4 PSI. Question is, do I replace the regulator and/or the gauge? As always, thanks in advance for your input.