Quote Originally Posted by roofcam
Should I use a 4-post switch, or one of the fused memory guards on a 2-post switch? I want to retain the clock and radio settings when the switch is in the disconnect mode. I see that NHRA requires a 4-post switch for use with alternators. I don't know what that does, but I don't need to meet any NHRA requirements. Thanks.

NHRA wants something more than a battery "disconnect switch".

What they require is a battery "kill switch", that will shut off the engine even with the energized alternator turning. You can wire a two post cut off switch to do this if you pay attention to which terminal side you have the alternator wired into.