I'm using the s/brake switch to control the fuel pump relay ground circuit.
I never use the s/brakes anyway, they are way too strong.
Another great one is to use an old style floor mounted dimmer switch, you
can put it up high out of the way. It is a "on-on" switch, so you wire one
side to connect the fuel pump to the ignition circuit, the other side to the
horn :)remember to switch ir with the ignition off or you get a loud
Can also wire any switch to ground the negative terminal of the coil, no
spark, no go.
One handy feature of the fuel pump shut off is when you are putting the car
away for a while, you can shut off the fuel while it is running and let the
carbs empty out so they don't gum up. Not reccomended if you use the fuel
pump/horn selector switch option.
There is a great site called http://the12volt.com/ all kinds of circuit