I believe you are correct, the difference being between pressure and flow rate.
To date I have purchased a pressure gauge and connected the Spectra sp8108 pump
(3.9 - 6.4 psi) along with a Mr. gasket pressure regulator….. waiting for the low pressure pump to arrive. Turns out the Mr Gasket pressure regulator is not accurate ( as I was advised )
Close as I can get is the actual pressure varies about 1 1/2 psi from the setting on the regulator.
Will see how the low pressure pump does when it arrives.
Next tool I need is low pressure hand (or thumb) pump and a gauge to accurately measure the carburetor fuel needle holding pressure.
