side note, the reason why that other pump was missing the 4th bolt behind the hose, is because on the updated service manual for ford, they actually suggest you leave the bolt out since it's useless and it makes it easier to remove the pump in the future if you ever need to work on it again. you can use all 4 if you'd like but i'm assuming the previous person who worked on that buick engine followed the service manual.
side note, the reason why that other pump was missing the 4th bolt behind the hose, is because on the updated service manual for ford, they actually suggest you leave the bolt out since it's useless and it makes it easier to remove the pump in the future if you ever need to work on it again. you can use all 4 if you'd like but i'm assuming the previous person who worked on that buick engine followed the service manual.
Why would it have 4 bolts and not 3 then?