A couple of things I have done troubleshooting ignition issues is to pull the distributor out of the engine and run it with a hand drill.
If you are getting a spark directly from the coil while rotating the distributor drive, but nothing at the plugs, it means you have an issue with the cap and rotor. For the ignition box to get a signal to fire, your pickup has to be working.
If you have an old OE distributor that worked before, I would give that a try instead of the MSD unit.
If you are getting a spark directly from the coil while rotating the distributor drive, but nothing at the plugs, it means you have an issue with the cap and rotor. For the ignition box to get a signal to fire, your pickup has to be working.
If you have an old OE distributor that worked before, I would give that a try instead of the MSD unit.