Gunk on fuel injectors (fuel leak?)

[CBR.worm]

My 165K G35 needs valve covers, as I started pulling it apart I found a surprising amount of gunk on the outside of the #4 and #6 fuel injectors. I don't know if this is common, but I guess I should replace the O-rings at the very least. At 165K and 11 years of abuse, should I be replacing the injectors or having them professionally cleaned? Is there something else I should be doing while I have it apart? I know Trav used to do fuel injector service, maybe he will chime in?

I appreciate any input.
Thanks!

 

[Trav]

Its not normal, probably leaking/weeping O rings, PM me if you need them cleaning.