Various o-rings/seals for Bosch injectors

[MrT]

I have been unable to understand what the seal and o-ring difference is for the Bosch L-Jetronic injectors is. My manuals are not sufficiently clear and the injectors I have removed from an '86 Spicer have seals with interesting cross-sections (nicely contoured and not circular or square). The upper seal that came out of the engine is nearly square with a step to locate the injector within retaining ring at center. A rubber seal on the nipple surrounding the actual gas spritzer orifice was yet more cleverly contoured (is this the "o-ring"?). There seems to be still another seal that may be stuck in the port of the engine. I purchased a set of Bosch seals for a VW, thinking the $4 for 4 cylinders was in interesting option rather than $7 per cylinder for some suppliers. The top seal on these is not stepped, so the top of the injector is not positively located if you use these. The bottom seal seems to be the size of the "o-ring" that fits on the injector nipple, but is purely square in cross section. It seems to fit into whatever is left in the engine, but I really don't want to experiment with a newly acquired car I am trying to get running again.

any helpful pointers would be appreciated.

Michael