I have Stewart Warner fuel pumps in both of my cars and both are relatively quiet when run and I don't notice any abnormal heat. The one in the 57, makea a clicking sound when it is pushing gas to the carbs, but once the carbs/lines are loaded it's whisper quiet. The one in the 34 doesn't click when loading, but it is a little noiser, probably due to location. The 57's is located between the gas tank and the rear bumper and the 34's is located on the frame near the rear wheel (a lot closer).

Could be the Smithy's don't let the fuel pump's sound get noticed.

I have a new spare unit and would like to find a couple more, since I don't see them advertised anymore for 12 volt systems. I have seen them for 6 volt systems.