As previosly mentioned, GM used a resistor wire instead of an external resistor. Turn key on and check for voltage at coil. 7-9 volts indicates that you have resistence. If voltage is higher, points will burn.
A thought: Do you still have the resistor bypass wire on the (+) side of the coil? You should have 2 wires on (+) side, one from the key, one from the starter. If not, it is possible that you are getting little to no voltage at coil during cranking.
The wire from the starter should come off the solenoid terminal marked "R".
