We've been adapting these distributors to stovebolt engines for years- - - -just cut the shoulder off the housing and drop it down into the block another 1/2 inch or so by using a shaft collar with a setscrew- - - -no gear or shaft modifications needed.
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!