Stud sizes (Ammeter & Starter Relay)

My buddy has a 1963 Dodge 440 (with a 383). He has asked me to help him with the Mad Electrical ammeter bypass. So, I'd like to get some things prepared prior to the job.

What size are the studs on the factory ammeter? My '71 Dart GT has #10 studs on the ammeter. Would the '63 440 be the same size?

Also, what size is the starter relay's BATTERY stud? Again, same as my '71 Dart GT? I assume the starter relays can/will interchange.

As always any guidance is appreciated.

Starter relay should be 5/16"

I'm not a fan of the Mad approach. I run a wire from alt to starter relay, bypass ammeter and leave the original black charge wire on the alternator (if in good shape).

Simple, no cutting of the wiring required. Feeds the interior using factory path.

I too don't agree with the Mad bypass. I do Nachos' bulkhead parallel bypass (only) & clean ALL terminals/connections (including ground paths). I like my ammeter (+ an added voltmeter) & relaying the AC/heater/headlights directly to the alt is a good move.

Ammeter studs are #10-32 and relay stud is 5/16"-24.

Thanks guys!

We plan to add a wire from the alternator to the starter relay stud, then a 2nd wire from the battery + to the ammeter "input" stud.

The headlamps are also going to be put on relays.

Interesting; what gauge wire (alt/start relay)?

We're adding a 12 gauge wire with a 16 gauge fusible link.