Z1 coil failure

Still in the process of resurrecting a '74 Z1. I have done the ohms check on the input and output per the specs and am getting good readings. Problem is that the 1&4 coil does not reliably fire one of the cylinders. At times it has fired both cylinders, but then it goes back to only firing one. Is this the way they normally fail or should I be looking at something else.

Thanks

If you checked primary impedence (ohms across power/signal input lugs) and it checks to about 3.5 - 4 ohms and you have about 15K ohms across plug wires, the coil can still be bad. Swap the coil with the 2/3 coil to be sure. See if the problem moves to the 2/3 plugs not firing once the coil is moved. I would replace with Dyna green 2 out coils if you find the OEM coil bad.