Crap - your pick up coil in the distributor is ok.
Double crap on the ignition coil availability.
Get one from *********.com for a 67 Chevy Bel air for $13.
67 1967 Chevrolet Bel Air Ignition Coil - Engine Electrical - Accel, MSD, Standard Motor Products - *********
Can't imagine a parts place would not have an old cheap chevy coil. Surely you have a bone yard or two around there. Buy two to be safe from the bone yards. :-)
If found to be the problem, then get a proper coil.