I Don’t remember the P/N of the Fluid Dampner I had on my 440. But I too had to have a spacer made to run the MSD crank trigger. I think the old ones were recessed so the crank pulley would line back up with the water pump pully

3520 pound race ready 1973 Street/Strip Dodge Dart - Stock stroke 440/727 10.49 @ 125.0 on 93 pump gas & ET Street Radials. More to come... ( SGT Miller) Proudly served 12 years in the US ARMY RESERVES support our troops