I should have said ignition system. The light I had was a relatively new unit with an inductive pickup. If I remember right the distributor was a Mallory electronic crab style.
I had that happen a while ago. My timing light that I had been using would not work on an engine with an electronic distributor. Borrowed a friends light and it worked perfectly. I have both a Sunpro and a Snap On that work well.
I think you have something wrong if you only have 55 psi compression. Do a cylinder leak down test to determine where the problem is. Try oiling the cylinder walls and retest to see if the compression comes up.
I've talked to Charlie several times about this situation. I prefer to run power valves so I don't run rich at lighter loads. I find this the way to go.