The real HEI fits. If it contacts the side cover or the block, a little careful grinding of the edge of the distributor cap or the block might be required. Stay FAR away from that conversion unit that uses the original distributor and some sort of cobbled-up adapter for an obsolete Chrysler Corp. trigger unit and a GM 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!