1932 Stude Six spark plugs

[Guest imported_32mod55]

I am trying to figure out the difference between Champion 2 com and 2 com L (long) plugs. I have several sets of each and they appear to be identical as far as all measurements taken from the sealing flange to the tips of the plugs. They both have twin ground electrodes and take-apart bodies; there are slight differences in insulator design, brass connector and knurling patterns. I believe they were both used in several tractor applications of that era, and the 2 com is replaced by Champ W18 or 518. Anybody know if 2 com and 2com L are interchangeable?

Thanks

32mod55@peak.org