I have nothing but contempt for Holley pumps, electric and mechanical. Have seen two mech pumps self destruct, with one lunching the cam lever pivot pin assembly into an engine. Running a Carter mech in my Kirkham for 5 years without a hitch. As for electrics, the Holley blue pump I originally ran in my car functioned ok, but sounded like a blender full of rocks. I finally chucked it and installed a Mallory unit and couldn't be happier. Reliable and much quieter. Love their carbs, but that's as far as it goes.
Bud