The two different types of vacuum advance control parts (group 2.410 in Tim's catalog link) are shown in the
Chevs of the 40s catalog. I believe that it is also required to use the matching
clamp/arm (group no. 2.414) for the controller. There was thread last summer concerning a
similar problem. If the arm/clamp screw is backed off does the distributor rotate?
Hoyt
