1961 Chevy Truck Start problems.

I have a 1961 Chevy Fleetside pickup that I have refurbished and have always had a hard time starting it. It will go a long time starting fine, but then run rough and then won't start. It is in that mode now. It cranks, but there is no spark. I replaced the ignition coil and still won't start. Using a voltmeter the needle jumps all the way over when touching the pos and neg terminals. The needle only goes below 10 on the ohm readout when touching the pos or neg to the center. But there is no movement of the needle when I touch the center of the coil and the center of the distributor. All of this is done with the key in the start position. Could I have a bad resistor? I checked it and the coil inside is fine. I bench checked the starter and it is fine. Where should I try next? Any advice would be appreciated.