I just changed the fuel filter on my 92 Z28 and both o-rings were missing in fact I remeber changing it last spring and I didn't have the o-rings on the fuel lines.
I havn't had any fuel leaks at all but I know my Chilton's manual says to make sure the o-rings are on.
Are the o-rings always needed?
I'm going to the dealership tomorrow to get some posi additive,I think I'll pick a couple o-rings up also but I'm really not looking forward to dealing with the whole fuel filter mess again!
Should I get the o-rings and put them on or will it be ok if I have no leaks?
Thanks in advance!

 

"No leaks" is a good thing. If it isn't broken...