The GM HEI coil has such a low primary winding resistance that it's necessary to use a big wire to allow it to come up to full charge on the magnetism quickly. Once the magnetic core is saturated properly, they use a combination of the inductive reactance of the coil windings and a built-in current limiter to prevent overloading of the transistor amplifier in the ignition module.
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!