You can put a diode in the green wire and hook it up with the purple wire.
I have a 60 Bel-Air project coming up, wish I would have bought that engine,,, All is well hope the same with you.sold it......then built a 409 (for the street) using my 427 crank out of my 348 now in my bubbletop. 409 crank back into my 348 for the biscayne.....that's why i'm looking for a steel shim headgasket. Hope you are doing well Dan