Originally Posted by turtle64b

There are some 3/16"ish spacers where the injectors meet the engine to ensure the injectors remain firmly in the rail and in the engine. If you do not install them, fuel pressure can force the injector further than desired into the block and lead to the top developing a gap between the injector and the rail. After a little cooldown, I felt the inboard side of the injector at the rail and I could feel the o-ring. Also, significant spray from between the rail and the injector upon priming the fuel pump by turning the ignition "ON"

If you look at the picture, the spacer is actually on the injector ("top" or engine side of the injector) at this point. How they got removed is beyond me...