Holley 1904, 1 Barrel Vacuum Check Ball
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.