You have a MOPAR ballast resistor. That one was used on some mid-1970's Chrysler products with electronic ignition. You need to buy a ballast resistor for a mid to late 1950's GM product, like maybe a 1959 Chevrolet or Pontiac, etc. V8 or 6 cylinder doesn't matter- - - -they're all the same. With the points closed and the ignition switch turned on, you should get around 9.5-10 volts at the + terminal of the coil. With the engine running, a 4 volt drop across the resistor should be about right- - - -14 volts in, 10-11 volts out is OK.
Jerry
