[vettestr]

Great advise about the alt. B+ or the starter battery side of sol. as hook up point for timing light. .
The other question I get at my shop all the time is how much timing and how do I set it up. The answer I give is put all the initial lead you can but limit total ( initial + mechanical ) to no more than 39 degrees. This answer is for non injected or computer controled cars. I use an inductive type light for ease with a dial to offset to zero to set up the distrib. in the car. This light is a must if damper is not marked beyond 15 or so degrees. You can use masking tape and put a temporary 20 or so degrees more on the damper if needed. A 360 degree tape is even better though.
If running much of a cam and a little higher C/R the engine wants about 15 to 20 degrees initial lead and then the delta of initial to total of 39 degrees. THIS MAY cause motor to turn over a bit slow when starting hot but just pump pedal 1 time before you hit key to make starting easy when hot.
Keep increasing initial lead until it pings under hard load (lug motor in a higher gear and excelerate from a low RPM) Once you find where it pings then stop and remove 2 degrees at a time until pinging stops, at this point remove 2 more degrees as your ideal initial lead setting. Subtract this number from 39 and that is amount of mechanical timing you need in the distrib. Mechanical is limited with spring tention and fine tuned by the advance fly weights.