Make sure you're getting power in "start" position. Some old cars/trucks cut power to the ign circuit in 'start' and the starter sent full 12 volts to coil. Upon returning key to 'run', the starter circuit cut out and the points dist was fed by resistance wire from ign circuit.

Preaching the Hot Rod Gospel according to the 4-stroke apostles:

Suck, Squish, Fire and Fumes