No spark

Hello, I have a slant 6 (1965 Coronet) engine in my newly purchased 1949 Dodge truck. The previous owner bypassed the 6 volt system and is using 12 volts just to get the engine running. I was told the engine ran with the way he wired it, as it is very basic. A toggle switch to turn the ignition on, a ballast resistor in line with the toggle and a push button to engage the starter. My problem is I have no spark. I get battery voltage to both sides of the resistor and to the positive side of the coil but no spark when the starter turns the engine over. All ignition parts appear brand new but I still replaced the coil, high tension wire and the condenser. I even brought back the new coil to have it tested and it checked out ok with the resistance test on both the primary and secondary side. The points are opening and closing. I know this is a very basic problem, but for the life of me I can not figure out why no spark. Any advise is appreciated.
Thank you,
Otto