Model T's up to about 1919 were powered by their own internal magneto system which generated AC current. The stud on the bellhousing as you call it is where that AC current leaves the magneto via wiring to the igniton switch. When Ford introduced the Lighting & Starting system, Model T's were fitted with a starter, a battery, a generator and electric lighting. Owners then had the oportunity to start the engine initially on battery power, and then switch over to the internal AC magneto once the engine was running.
NEVER, NEVER, NEVER APPLY ANY EXTERNAL POWER SOURCE TO THE MAGNETO CONNECTION ON THE TRANSMISSION - YOU WILL WIPE THE MAGNETISM FROM THE 16 MAGNETS BOLTED ON THE FLYWHEEL .... been there - done that - got real mad ....
The firing order is determined by the wiring harness from the round timer (or commutator) on the front of the engine to the coilbox which houses the four spark coils. Those four coils look deceptively simple, but they are anything but that. Mal-adjusted and/or bent contacts quickly turn a great running Model T into a rough running putt-putt. There are only two ways of correctly adjusting a good set of contacts on a coil - using a vintage handcranked coil tester or using a Strobospark - there is no other way to PROPERLY set up those contacts. Just because they buzz nicely doesn't mean they are set up correctly. I mention this only because it's true!
The camshaft roatates counterclockwise, and the wiring is as follows:
The terminals, as viewed when looking at the timer from in front of the car, are as follows:
Top-left timer terminal - cylinder 1 (closest to radiator)
Bottom-left timer terminal - cylinder 2
Bottom-right timer terminal - cylinder 4 (closest to firewall)
Upper-right timer terminal - cylinder 3
These wires go to the upper row of four coilbox terminals. The Next row of terminals below those obviously are the sparkplug wires as shown in the attached photo.
This is enough to now make you dangerous. It's your job to get the books mentioned and learn the Model T electrical system - it's very easy. Those pesky coils are what's not easy to the average person without either one of the two testers mentioned above.
Good Luck, and Good T-ing !!
Regards all,
Garnet