if i read your post correctly you are running an hei distributor? if so make sure that the spade connector is actually on the male terminal coming from the coil. i have seen this many times where people get the connector wedged between the male terminal of the coil and the plastic housing of the cap. when this happen it feels like it is connected on the male terminal, but in fact is not.
this is a very simple easy check before you start replacing stuff.
AP