My round track engines with the required "stock-appearing" HEI systems for the class we were running were turning 7K + RPM to the consternation of all my competitors whose distributors started to spark scatter and miss at around 5500. It's a very simple modification.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!