Check the fuel pump before replacing it. The 60-year old tank and feed line may have become clogged with sediment. The 51 is a gravity feed to the pump, so it should gush out if you disconnect the hard line at the pump. I had a 53 3100 that the feed line was clogged enough that the carb bowl would fill at idle, but it couldn't keep up with the fuel demand while driving. It would start and idle fine. Then after being driven about 1/2 mile it would quit.
It would restart and idle okay, then die again just as I got back to the driveway at home.
regards,
Leon
