Specialist recommend that the point gap be checked and reset with every oil change, usually around 3,000 miles.
Changing the point gap changes the ignition timing because it changes the dwell. If the new points are reinstalled with the correct gap, the timing should remain the same.
The point gap can be checked with either a feeler gauge or a dwell meter.
- When using a feeler gauge, position the distributor cam so that its lobe is against the rubbing block that holds the points open. When the cam turns to the position between the lobes, the points will be closed.
When adjusting the point gap, the rubbing block is against the lobe on the cam. Courtesy of Sun Electric Corporation.
- The dwell meter measures the length of time in distributor degrees that the points are closed in one revolution. Dwell is less the more cylinders there are.