Vacuum Check Ball
The 1904 carburetors for automatic transmissions have a nylon check ball and retainer clip that goes in the float bowl body where the throttle body mounts to the float bowl. The manual transmissions did not need this. In our Holley kit # K421, this check ball is plastic. This vacuum port is used to feed the distributor advance vacuum line.
Adjusting the Accelerator Pump Stroke for Seasonal or Climatic Changes.
The accelerating pump stroke can be adjusted for seasonal or climatic changes by changing the position of the pump link in the throttle lever. The hole in the lever nearest the throttle shaft is the normal setting and should be satisfactory for nearly all operating conditions. If a richer accelerating pump discharge is desired for extreme cold weather operation, set the pump link in the outer hole in the throttle lever. Pump link position can be changed by removing the cotter pin at the lower end of the pump link, moving the pump link to the other hole, and re-installing the cotter pin.
1904 Float Bowl The Holley 1904 glass float bowl and metal float bowl are interchangeable. The glass type of float bowl uses special screw clips. You must use these on the glass bowl, or it could break.
The Holley 1920 float bowl will also work on the 1904, but the baffle will need to be removed 1st. The baffle simply slides in and out.