When I electric fuel pump convert a rig, I always run fuel pump power through the switching pins on a three prong oil pressure sender. I used one from a '77-9 Cadillac DeVille because that's what I had to hand, but it's just a basic oil pressure sender with 1/4" NPT threads. The copper colored blade is the dashboard light, the other two switch the electric choke, so when the engine runs there's power. I don't have an electric choke, so instead it switches the fuel puimp, which only draws an amp or two. I also ran a lead from the starter S terminal, since that one only provides power during cranking. Notoriously unreliably.. but at least it's there in theory to reduce cranking time if the fuel bowl is dry.
So that's my safety feature, the fuel pump can't run if the engine isn't.
