904 extention housing bushing
You will need a new gasket for the extension housing and the plate that covers the snap ring. The bushing can be driven in or out from either direction and make sure to line up the lubrication hole in the bushing with the slot in the housing when driving in the new one. When your removing/re installing the extension housing put the shifter in 1st gear to get the park rod in/out of the extension housing.