I was swapping out my injectors and noticed on 2 cylinders one rocker arm socket is missing the little plastic retainer thing. Should i be worried about this or is it not a big deal they are made of plastic and im not sure how long they have been like this.

 

I was told not to worry about it the rocker can only move .010 on the intake side and .020 on teh exhaust side. so no chance of the rocker coming off if the valves are within spec

 

As long as you don't over-rev or over-boost it and cause valve float, should be ok. That beind said, I would look into what that piece costs and correct it if its reasonable. Hate to cause some serious damage for a $.50 piece.