Well, I have three sending units, the one on the right (1st pic) is labeled as ‘90 23gal. The left and right one both have a tag with 89560 01859 (my SWB and LWB have this) middle has 5345. All three look the same except as follows. The right one has a different upper pump bracket than the other two. The middle one has 90° hoses coming to it. Anyone have any insight?