Another battery in trunk question?

I have the gm Hei setup for ignition. Is it possible to run a 4 pole cutoff switch and just split the blue wire that runs to the alternator and run each side back to the cutoff switch? Then run the battery cable from the original starter relay to the cutoff switch, then to the battery? My alternator is a stock 60 amp 2 wire. I run a magnum engine with the stock mini starter.

All the schematics I see are for 1 wire alternator.

Thanks Tom