Not all ladder bars have them
Don't do anything with them Art, OK. They are redundant unless you need to make a correction in the pinion angle that the present setting can not reach. Just think about it, as you are setting the pinion and you have too much angle on it due to using the lowest hole in the chassis. This setting may require shortening the lower rear adjusters to get your 2.5 deg pinion angle because it may have too much when you change to a lower hole than you use today. You do not want to over extend the upper adjusters to have less than 1.5 times the thread diameter into the female end of the adjuster. Now quit over thinking this simple suspension and go set it up Art.
Bruce