[PeteKz]

Review the basics: Compression, fuel, spark.

I'll assume for the moment that since it eventually fires and runs, you have spark at start too. However, if the cap has corrosion in the plug towers or internal poles, or the rotor has the same, either scrape them clean or replace the cap and rotor. For testing I would just scrape them clean.

First test, becuase it's fastest and easiest: spray starting fluid into the intake. Does it fire? If so, then you are lacking fuel at start up. If not, then probably too rich or flooded. Also try starting from cold WITHOUT pumping the pedal first. Then try just one pump.

After that, test compression. No need for leak down test at this point, just a quick cranking compression check for all cylinders within 10%, and within the range of acceptable values. Since you will remove the plugs, do this after you try starting from cold, but without the engine firing, to see if the spark plugs are wet (indicates flooding). While you have them out, check for spark, to verify the assumption above.

My strong advice: get the engine starting and running correctly BEFORE changing the ignition. Don't complicate your troubleshooting by introducing more changes and variables. "One thing at a time."

If you decide to go to the 123 distributor, it eliminates the Pertronix. It can run directly to the coil, and thus eliminate the CDI box too.