There's a way to retro-fit a point-type distributor for the early 250 with a reluctor and a pickup coil for a MOPAR slant 6 and use it to trigger a remotely-mounted GM HEI ignition module. It's not a bolt-in fit, but it can be done with a minimum of machining. That setup would be far more reliable than any of the aftermarket conversion kits, and still have the advantage of using non-proprietary parts with the resources of major manufacturers' R&D behind them. The MOPAR six distributor repair kits are available on Ebay.
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!