Re: Spark plugs
what kinda tune up did you do? cap, rotor, plugs, points, condenser, fuel filter (s), dwell and then time it, idle speed adj.? how did you rebuild the carb? carb totally disassembled and soaked in carb cleaner, scrubbed clean then blowed out all passages with compressed air? all new gaskets, all specs set proper on the carb. per the book?
your description sounds like the cold fouled plugs that are mentioned in the book. from s/m #2, "dry, black deposits indicate rich fuel mixture or weak ign. clogged flame arrestor, flooding carb. sticky choke or weak ign. components all are probable causes. if only one or two plugs in a set are fouled, however, check for sticking valves or bad ign. leads"
how did the compression numbers turn out?