Just use an original equipment Delco HEI from an early to mid 1980's Chevy 350. Be sure to use the one with a vacuum advance, not the one with the 4-wire electronic advance plug on it. It's a drop-in fit other than needing to run a 12 gauge or larger wire from the ignition switch to the HEI. RUN- - - -do not walk away from the Pertronix or other Rube Goldberg proprietary electronic systems.
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!