Here are the stock fuel pump specifications :

71-73 A12 2.4 psi (0.18 kg/cm2) 450cc/min
1974 A13 3.4 psi (0.24 kg/cm2) 450cc/min
1975 A14 3.8 psi (0.27 kg/cm2) 600cc/min
1976 A14 3.0-3.8 600cc/min

Since these all use basically the same carb, you can see the exact pressure isn't so important ... Just make sure the flow is enough.

The flow test is done at 1,000 rpm: disconnect and plug the fuel line. Start the engine, and let the fuel go into (at least) a one liter container. Turn the engine off in one minute and measure how much gasoline was pumped. Be careful ...

These are US specs, but probably the same for other countries.