Simply stopped

Also, ignition points or electronic ignition. ...............

^^THIS^^ need more info

You need to learn to troubleshoot. If this is points, you can almost troubleshoot by looking for spark at the points, but a 12V test lamp is much better, and a multimeter better than that yet

Get a bag of clip / test leads from Radio Shack

If you have Pertronix / Mopar / HEI but not MSD or other CD, jumper 12v to the coil + and see if it runs

Test for spark USING THE KEY

It is important to understand that ................

Using the key to crank..............

VS jumpering the starter relay sets up different situation for ignition voltage

One is "run" voltage going through the ballast and is dead in "crank."

"Start" feeds 12V direct to coil + "IGN2" the brown wire or bypass circuit. If this is not working it will not fire with the key.

Hook your lamp / meter to coil + Turn the key to run. Bright light? dim? nothing? 12V? far less? nothing? Points might be open, might be closed

As above, a bad condenser or coil or points not breaking / making can shut ya down right there

I might not be back right away, been busy this week