Hi. Been fixing a 1987 F250 with my son for him to drive It has the 6.9 IDI. We are replacing the entire cooling system, and almost have it back together. The water pump pulley has a spacer/disk with the 4 bolt holes. I’m ashamed to say that we can’t remember if the spacer goes behind the pulley against the WP hub, or if it goes in front of the pulley towards the fan...? If anyone can help, we would greatly appreciate it.