bergmanj--
Here is an item from Service Letter P-297, dated Feb 28, 1956.
I ran across this after I replaced my wires in the new looms per the instructions in the shop manual, which appear to be the same as the Casco instructions. I havent had any misfiring, but if my 56 292 seems to be idling a little rough, I wonder if I should make this change. But then I look under the hood and remember thinking that whoever designed the Y block wiring and looms etc should be shot. Maybe there's more room to work on a Bird, but it's painful in a pc. Anyway, take a look at the Service Letter item: