I have a 71 240 ,I recently installed an electric fuel pump and removed the mech pump.the pump is working but since I installed it fuel is leaking from the banjo bolt on the float bowl of the carbon the left(closest to front). I cleaned the float but the problem persists.Any suggestions?,is this problem related to the new pump or just a coincidence?

What is the pressure of the fuel pump? The stock pump specs are 3.4 to 4.3 PSIG, so the electric fuel pump should provide a similar pressure.

holly 12v/7psi/97gph

I think we found your problem. 7PSIG>4.3PSIG. You need a pressure regulator downstream to use that fuel pump.

I was told that a regulator was not necessary,pump rec by motorsportsauto auto. what is in volved with adding a regulator

Steve is correct, you do need a regulator. However, the banjo fitting should not leak at only 7 psi. You may need to tighten it a bit more or replace the crush washers to get a better seal.

Installing the regulator is easy. We use a simple in-line regulator with the same Holley pump and it works fine. This type of pump does not cost much and should be available at most auto part stores.

That banjo has very thin washers, but they make the difference. Mine squirted fuel like fountain without them.

what's wrong with the mechanical pump anyhow?

Be sure to check the torque on the banjo fitting. It should have a soft, probably brass, sealing washer on each side. Naturally, we tighten things to stop leaks, but banjo fitting faces can distort if too tight. Good luck.