fordc,
If you've changed everything about the ignition system and this still happens, and happens the same way, you may need to check the fuel delivery the next time it happens. Also, sometimes, when an old distributor cap or rotor gets hot, it will start acting up in this manner. It's just a chance, but it's worth consideration.
Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon