Ron,
At some point, if you cannot figure out what the problem is, you might have to start "from the beginning" by checking out each part and system in an orderly fashion.
I suggest buying the following parts and change them one at a time. It will not be a waste buying these parts because you should probably have them (and carry them as spares):
Spark Plugs
Spark Plug (Ignition) Wires
Points
Rotor Condenser
Distributor Cap
Fuel Filter(s)
Then, in order of increasing expensiveness:
Coil
Fuel Pump
Distributor
Carburetor
I carry all of the above items (plus other items that might break but would not cause your problem, such as a fan belt). The only one of those parts I have needed over the last 8,000 miles is the fuel pump (twice a few years ago - perhaps alcohol in gas affecting the seals?).
Also, double/triple check all your electrical connections (and wires) in the ignition system, and check all you ground cables and connections.
Keep at it, and good luck.
