273 Engine will not start - Ideas?

Thanks everyone for all your inputs on this, now here is the latest status update and what I went through to get there. Starting at the end, let me say I finally got it running. I started out pulling everything out of the car and setting it up on the bench. Bench tested the entire ignition system excluding the switch. The test was done using the #1 plug wire with spark plug and had sufficient spark at the plug and appeared to be consistent. This was done with the new coil I had installed and the car previously ran on. I also tested with my old coil with the same results but decided to use the new coil when I put it all back in the car. Once all installed, car would still not start although it would fire a couple times but not catch and run. So things that were not included in bench test was wires, cap, and rotor. Changed cap back to my old original one, still no success. Replaced the Rotor, still no success. Also let me insert here that each time trying to start, engine would fire once or maybe twice but would not catch and run.

So then I suspected the switch as a possible problem and so check voltages pre and post ballast resistor with key ON (had done this before but checked again), voltages were what they should be - battery was 12.5v, pre ballast was 11.5v, post ballast was 6.5v, all considered normal. Post ballast resistor during cracking was 10.5v, again considered normal.

Moved to testing wires at spark plugs with inline spark tester (light kind). With each test, first spark was bright, second was less bright, and third was real faint - didn't make sense. All plugs did the exact same thing. Subsequent checks eventually got to the point of no spark at all. Purchased a spark gap tester and today plugged it directly into the new coil - no spark at all no matter what distance set at. Pulled out the old original coil and did the same test and had tremendous spark at the 10mm setting. So conclusion was that new coil went bad and was going bad slowly through all the testing. Proceeded to check wire resistance and found that average was about 7.0 on the 20k scale. Decided that those were fine so plugged everything back in turned the key and viola fired up immediately and ran.

Final conclusion is that the new coil went bad progressively until it finally failed completely. Who would have thought. Generally a coil was either good or bad, at least that's what I thought, not progressively failing. Needless to say it was really good to here the fish rumble to life again. Now to continue where I was 7 months ago - set idle mixture screws and idle speeds, etc..

Thanks everyone for all your inputs. Log this one as the odd scenario in case someone else has a similar problem.