I believe the original 6V ignition with points and condenser will have a coil that can produce maybe a maximum 30,000 (30KV) volts but it only takes around 8-12KV to fire a stock spark plug under normal load. Being that you already have the Pertonix Ignitor, I would go with the company's recommendation.

"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."