They are called "injector retaining clips" and they are mildly important. If the rail and injectors are already in place, then they don't do much. But they do keep the rail and injectors as an integral unit for installation or removal. Thats important when you are trying to "pop"all of the orings into place. Make sure you use plenty of vaseline on both ends of the injectors when installing. Pick up those clips at the stealership or the junkyard and you can put them on without removing the rail again. But ultimately, its the 3 bolts on the rail that hold it in place and the orings make the seal, not the clips.
'89 XJ Laredo 4.0L, AW4, NP242, Dana 30, 35 w/Lock Right, 5.5" lift, 35x12.50x15 Uniroyal m/t
'88 XJ 4.0L, AW4, NP231, Dana 30, 35 w/Lock Right, 4.5" lift, 31x9.50 SuperSwamper on salvaged 15x7's
'87 XJ Pioneer 4.0L, AW4, NP231, Dana 30, 35 w/ trac-loc, currently stock, 8" lift one piece at a time
[QUOTE=mdonohu1]i sweat your nuts. badly.[/QUOTE]