[Hoop]

Mike, I'm working with "quite possibilities" here. I haven't come across anything that states one way or another what caused the change in distributor design.

But, consider when it occurred. Europe already fully involved and the Japanese ripping through Asia. A world wide war was unavoidable.

With absolute certainty aluminum was going to be a deciding factor. Not recycled stuff but virgin aluminum was required for aircraft production. The War Production Board was in a frenzy very early to secure sources of raw materials. Aluminum production in the US was nothing compared to what it would become during the war.

In one year Ford could save maybe 200 tons of aluminum by changing their distributor design. I'm guessing again but that sounds like a worthwhile savings.

Didn't they manufacture some crabs in cast iron during the war?

Note that early KRW timing fixtures are aluminum ... they changed to cast iron.

It's one of those things. Which design change caused which design change?

Anyhow, interesting discussion for those of us who also respect the helmet.