[Cliff R]

Any stock vacuum advance unit can be quickly made into any amount of advance one would like. Here, I simply braze up the slot and refile it to reduce the amount of travel by the arm. For most well prepared street engines with medium compression ratios and a well chosen cam, intake, exhaust, etc, seldom is more than about 8-12 additional degrees of timing needed from the advance. I've seen several other methods used to control the amount of movement of the arm on the advance, including using a small self tapping screw and washer, epoxy and welding/brazing. For distributors prepared here, we reduce the travel to about .100 to .125". This will have the unit add about 8 to 12 degrees. Use a small drillbit as a gauge when modifying the unit.....Cliff