Im putting new plugs in my 2000 ss camaro they are AC delco 41-110 they are set at 040 should change them to 060.

 

No experience with the ac delco's, I use NGK's myself, tr6's or 55's if a colder plug is needed. Seems a lot of other people do as well.

.040 is probably a bit toght for a mostly stock NA combo. I would however, gap them tighter than GM's f-body recommendation: try .050. People report better/smoother idle, and maybe even a tiny bit better performance with that gap. The Vette's are also gapped to that spec, so it wont harm anything.

 

Got the 41-110's in my 99 Z28 set at the stock (.040) gap and haven't noticed that much of a difference at all to be honest. Originally had the stock 41-952 (.060 gap) in there. A lot of guys in my area run the ngk tr55's and love em.
The reason gm went with the 41-110's was for a more "fuel" economical aspect. Before the plug change on my car I was getting an average of 27mpg, and it stayed the same after as well.

 

Ummm... Stock gap is .060" GM updated the recommended plugs to an iridium tip gapped at .040" for idle quality, not fuel mileage.

To the OP: NEVER CHANGE THE GAP ON AN IRIDIUM PLUG!!!!