The tip of the rotor should be able to move clockwise about 1/8"-3/16", and spring back CCW to its original position when it is released. That equates to about 7-8 degrees of distributor rotation, or 15 degrees or so crankshaft degrees of advance. Add another 10-12 crankshaft degrees with the vacuum advance under high speed and light throttle conditions for best cruise performance. A distributor tester or a delay-flash timing light is best for checking actual engine performance.
Jerry

Last edited by Hotrod Lincoln; 11/13/2013 12:33 AM.
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