f.i. question
 

79 3.0 sc injectors feel loose can move them with hand easily this cant be norml?

They are held in by rubber o-rings. The rubber gets pretty hard and does not seal like they used to.

Grab an injector and pull it straight up and out (with fuel line attached). Feel the o-ring and I bet it's pretty stiff from age.

In my case, the injectors are tight in the sleeves, but the sleeves are loose when car is not running. I noticed that when the car is running, they don't move as easily due to vacuum. I figured this was normal or maybe I read it was normal?