Size of hogshead magneto post opening '09-'25

[Moxie26]

Aware that the 26-27 hogshead accepts a magneto post assembly with a tapered half inch thread similar to the spark plug thread. The earlier magneto posts are held with three screws. What is the size of the opening for the earlier magneto posts?

[DanTreace]

Aware that the 26-27 hogshead accepts a magneto post assembly with a tapered half inch thread similar to the spark plug thread. The earlier magneto posts are held with three screws. What is the size of the opening for the earlier magneto posts?

Generally about the same, approx. a .740" opening, in the hogshead, the early mag post insulator is about the same o.d. as the threaded Improved Car mag post.

[Moxie26]

Thanks very much, Dan !

[John kuehn]

The question made me wonder too.
So here’s a pic of a 19-25 transmission cover from my T parts stash. It’s really close to 3/4” .
If I could find the 26-27 mag post I have it would interesting to know if it would go directly in the older cover even though it’s threaded. Was it a change for the better because it was threaded or??

[RajoRacer]

There was an adapter available back in the day to use the threaded mag. plug onto an earlier trans. cover - I'll get a photo later.

[RajoRacer]

I believe this might be a Ford part - I'd have to scout out the later price list of parts. I also have a NOS in the box "Easy2Kleen" accessory magneto contact similar to the one in the photos - I didn't get it out of the showcase ! This type of contact was way easier to remove & clean !

[Moxie26]

Very interesting... Thank you Steve.