318 problems

There are several ways to fix this or at least get you close. I'm sure some of the other guys on this forum would have a better suggestion, but here's how I'd do it.

Pull all the plug wires and take the distributor cap off. Put your distributor down in the engine (without the cap on) and get it "seated" into the slot on the top of the drive gear.

Take a narrow piece of tape and "mark" the distributor case where the rotor is pointing. Put the cap back on and start putting your plug wires back on starting with the number one plug wire lined up with your piece of tape.

Follow the firing order around clockwise, putting the plug wires back on one at a time. This will get you close, you may need to rotate the distributor a little counterclockwise to increase timing or clockwise to retard it.

These old engines are pretty forgiving and if you can get close enough then you can set the timing with a light after you get it running.