Please pardon my intrusion. 74 Catalina? Nice car. If I'm not mistaken the ignition systems of the GM's
were modernized to HEI systems beginning in 1974, which eliminated the points and condenser style.
I know from experience that the ignition module that replaces the points/condenser can and does
eventually fail in a couple of ways. The car will run terribly if it runs at all; or after having shut the car off it
will simply refuse to start again until the module is replaced. These modules are heat sensitive and must
be installed with a layer of dilectric grease which is often supplied with the new replacement module. It is
also my experience that the only modules to use are the authentic GM replacement parts and not the
offshore garbage as the counterfeit modules do not have the correct ignition dwell for optimum performance.
If the ignition system in the Catalina is indeed an HEI unit and the ignition module has not been changed;
that is where I would be looking for your problem. They're not overly expensive or too difficult to change and
you will find it right under the distributor rotor button, held down with a couple of small screws. I hope that
this helps.