[Dave at Pelican Parts]

If a valve actually dropped, it would make a horrible racket as the piston smashed into it.

Valve seats can drop and not cause valve-piston collisions, but they will cause a loss of compression.

Verify fuel and spark on all four cylinders, just in case.

A failed Pertronix usually just won't give you any spark at all. I have heard of them starting to fail and giving inconsistent sparks, but that is less common. Still, it may be worth trying points again to see if that helps.

Once you know you've got spark and fuel and compression, you can check the static timing of the spark. You can do that by setting up the motor to TDC for one cylinder, and using your extra spark plug on that cylinder's plug wire, tweak the distributor until it sparks right at TDC. That's not the correct timing, but it is more than close enough to start. (If you can get your engine to run at 3500 RPM, then use the regular timing instead of static.)

After that, the question is the amount of fuel. Too much or too little...

--DD