Im currently running autolite 104s gapped .060 could this be causing rmm codes to be set off,should i regap them, the reasoning for this question is alot run 104s,605s,and ngk iridiums for my setup what is the best in your opinions.Im just wondering if 2 stages colder which i have is to cold for it or not

I personally will only use a/c delco plugs in my gms. In my buick i am going to put a/c delco iridium plugs in it. The factory gap is 60 thousands. So thats what i am going to gap them at.

Paul...you should be running Autolite 605'*. at a .50 or .55 gap. Your running too cold of plug for your set up.

On a stock, or very lightly modded set up, the 605 gapped at .055. Once you start bringing up your boost levels a bit, then drop to a 104 and gap .050 to .055. You really wont need the 104 until your boost is over 10

I thought so,when i bought them i got my advice from not such a reliable source.So i will change them its not that much money or time.I dont see myself dropping pulleys or anything untill at least spring,summertime when i have more money