The original ignition was the dodge "lean burn" computor.I replaced the distibutor with an electronic distributor with mechanical and vacuum advance.I used a HEI module from a 1980 gm distibutor to control the coil.The original was not advancing the spark,all I had was initial advance.
GM HEI conversion (A 'How To') - Dodge Talk Community Forum Slant Six Forum, :: View topic - HEI Electronic Ignition Retrofit How-To The links above will explain further.