I ran electric pumps for a while, and ended up throwing them away. I will never do that again. The fuel pressure varies too much. Holleys don't like pressure changes.

When you are only idling at a few inches of vacuum you can really tell the difference.

Were you running a fuel pressure regulator? What type of pump were you using?

I had a few combinations.

I had a Mallory pump and regulator. It was one of the comp series. It worked the best, but burnt up.

I had a Holley red pump. They are a Catch 22. Electric pumps work best closest to the tank. Regulators work best closest to the carb. No matter where you mount the red pump, it is the wrong place.

I had a Holley blue pump with regulator. The regulator they come with isn't strong enough to regulate it's own pump. There are a lot of other people that I have discussed this with as well. The pump will eventually overpower the regulator, and flood the carb. You end up with a gasoline fountain under your hood.