To set the total spark advance you'll need either a delay-flash timing light, or a balancer with degree markings all the way to 45 degrees or so before top dead center. Some places like Summit or JEGS sell a piece of stick-on tape that goes on the balancer to read total spark advance with a conventional timing light. Total advance is a combination of initial timing, centrifugal advance, and vacuum advance. Set the initial advance at 8-10 degrees, leave the vacuum line disconnected, and rev the engine up to about 2500-3000 RPM or so. The combination of centrifugal and initial advance should be around 36-37 degrees. If it's not correct, adjust the distributor housing to get the right reading, and let the initial advance fall wherever it will. Sometimes it will be necessary to modify the centrifugal system to get good starting and midrange power and still stay below 37 degrees of centrifugal advance. Connect the vacuum line, and rev it up again. With high RPM, low load, (not pulling a hill, passing, etc.) the vacuum advance should add 8-10 degrees of advance for good fuel economy. As soon as you tip the throttle in to pull a hill or pass, etc., the vacuum advance will go away and you're back to the 36-37 degree maximum setting. Adjust the vacuum chamber to get the desired additional advance with vacuum applied.
Jerry
