slant six starting problems

Somewhere on this site I have written numerous times, a step by step on troubleshooting Mopar systems

Remove the ECU and clean the ECU and firewall and remount with star lock washers. The ECU MUST be grounded. MUST. Remove ballast, ECU and distributor connectors, and examine for corrosion. Work them in/ out several times, especially distributor connector. Examine the distributor pickup / reluctor for rust and debri, and strike damage. Wiggle the shaft and look for play. Obtain a .008 brass feeler (inches not metric) and check reluctor gap. If you hook an AC multimeter to the distributor connector and crank the engine, the distributor should produce about 1V ac. If you turn the key on, and ground one of the two (try both) distributor harness wires going to the ECU it should produce a spark

9V cranking at the coil is too low Try hooking a clip lead from the coil + to the starter relay battery stud and crank the engine.