I think what junkyardjeff was refering to was a resistor on the primary portion of the ignition system also commonly refered to as the balast resistor. If the current running through your primary system is to hot (not spark plug or coil wires), then you could be burning points.

I don't remember exactly how Ford did their resistor, if it was built into the original wiring harness, the coil (as jeff has suggested) or if its a stand alone resistor. I can try to look it up. If the newer distributor does not have a resistor after the coil, then the current running through the points might be hotter than originally designed and thus burning the points.