Right now I'm running off of the ignition, but I just bought a early 80's VW Rabbit CIS fuel pump relay. It runs off of the tach signal, if no tach signal it will turn the pump off. Starting isn't an issue as the carbs have enough fuel in the bowls to start. Only issue would be first dry bowls start, would be easy enough to install a NO push button switch.
Relay part number 321 906 059C the one I got has a 15a fuse built right into the top of the relay.
You could do a similar thing with a generic DTDP relay and run it off the oil pressure (idiot light) switch, but it won't be as fast reacting as the Rabbit switch.
There's also an inertia switch from a Ford (IIRC), but guys say it trips every time you hit a bad bump, simple to reset.
On how I made my relay board delete engine harness go to post #150 of my engine build thread. You can get the connector from member Perry Kiehl, he also makes full conversion harnesses.
Since I'm cheap I made a male connector by hacking a female connector from an old engine harness.
http://www.914world.com/bbs2/index.php?sho...9913&st=140