Timing light troubles.

I would just like to add to the OP sometimes those old lights are actually telling the truth when they fail to illuminate, on a particular plugwire.Sometimes if a plug or wire is failing it might do that.The proof comes when you move the trigger around to different wires and then the problem is not there. Im not saying this is Your problem, just that I have experienced it.Usually your ear will tell you when a cylinder goes down at idle.
-Rustys method of balancer marking works. I have used it during tune-ups on stock type engines.It is, however, heavily dependent on the person doing the marking, and the tools being used. Its easily possible to be out some, to a few, even to several degrees.
-Another alternative is to purchase a Timing Tape, that you stick on the balancer. It comes pre- marked for timing and valve adjustments. Its best to prove true TDC with a piston stop before sticking it on. Theyre usually black with white marks and lettering. A cheap low-powered lite sometimes has trouble illuminating it, esp. in daylight. A good lite has no problem.And the dial-back is no longer a must-have.
-Enjoy your new tool.