AC type G12 plugs (or modern replacement) Gap

[BryanD]

I've seen on a couple sites (such as: http://1931chevrolet.com/specs1.htm ) that the plugs for these old engines should be gapped at 0.040" rather than the (widely reported) 0.025". Can anyone confirm or deny this practice? The site I quote above is for 1931 Chevrolet, but I'm interested in trying this on my 1932 Plymouth which originally used those same plugs.

[BryanD]

OK, I went ahead and re-gapped the plugs. They were actually at about 0.022" and I reset them all to 0.035". Definite and noticable improvement in the idle and power delivery also seems smoother. Not sure if going all the way to 0.040" would be any better. I may try that (eventually) next time I have the plugs out.

[rwoods]

You may also try two or three more degrees timeing to go with the increased plug gap.It worked on my chevrolet as well as the model A.

Let us know how it worked.