360 Running Issue(s)?

Numba ONE

Unhook the tach

2. Try "hot wiring" the ignition system to eliminate ALL in - car harness wiring. Identify where the ign switch feeds the ballast (this is a 2 terminal ballast, right?) and hook into that with a nice big wire, at least no14, and run it out to something "solid" such as the big battery stud on the starter relay. Note that this WILL power the vehicle igntition until you unhook it.

Make sure you have compatible ballast/ coil. Did you buy 'em in a kit? or just a new MP distributor?

Be SURE of your ECU ground.

Remove and inspect all ignition system connectors, the ECU, the ballast, the distributor. Look for corrosion, "work" them in/ out several times to scrub the terminals clean, and "feel" for tightness in the connectors.

Consider replacing the ECU pigtail and distributor connector (or the harness) those connectors CAN break internally. You can wiggle them, while running, though, and get an idea.

Check charging voltage at the battery, just for drill. Warm it up, get the battery "normalized" and see what you have at a good fast idle.

When running, feel the coil (NOT the ballast!!!) for heat, and wiggle connectors, especially the bulkhead connector.

I WOULD at least temporarily, run a big wire, at least no. 10, directly from the alternator to the battery (starter relay stud)

S' all I can think of for now.

!!!OH!!! Look at the coil Is there a capacitor (condenser) on the coil? Which SIDE of the coil, (should be on positive side) Unhook it for now if there.