Getting rid of learn burn.

All any Chrysler factory type ignition needs is a switched 12V signal. That's it. I would find whatever switched 12V is feeding the Lean Burn system coming from the factory harness before it gets to the lean burn and use it. Wiring diagram and test light are your friends. If it was mine, I would use an early to mid 70s Carter BBS or BBD, the one or two barrel respectively, whichever it has.