Looking at the top of the distributor, turning it CCW advances the timing. CW is the retard direction. You can use a timing light on 6 volt systems, just use a 12V battery to power the light and trigger the flash from either the #1 or #6 plug wire. The ball and pointer will align no matter which one of those cylinders you use as a trigger point. My Snap-on timing light will also show how many degrees of advance the centrifugal and/or the vacuum advance provides so I can check initial, centrifugal, and vacuum advance to get a total picture of the timing system. A delay-flash timing light is well worth the investment!
Jerry
