You only have dwell if you have points, am I wrong?Looks like on the 5.0 the White-Light Blue wire connects directly to the coil from the ignition pin 11 (run) with no resistor.
I'd wonder if the TFI module is bad and burning out the coil with too much dwell or something?
sounds plausible.You have to have some charging time for the coil, so, If you have a coil, you will have dwell. On electronic systems, there is no adjustment available, so no one talks about it.
too long of a dwell will burn out a coil quicker than most other things I can think of.
With no ballast resistor in his system, that is the only thing I can think of.