They will work in an LNF, though, which is what this thread is about. LSJ is the odd man out when it comes to plugs - all the others use the same plug.

 

so whats the part number for ngk iridiums for our t/cs?

 

I wouldn't waste your money on iridiums.

 

Ok, so I bought the autolites XP iridiums. I haven't installed them yet cause I really don't know the exact gapping. I've read here .035, .030, .029. Which one should I do. The reason for me changing the spark plugs is ause I have been getting some insane backfires. Can you guys help me? I have them in my hands and ready to go outside as soon as I get an answer.

 

Stock is .035 . Different car's can like a different gap so i would test . Are you having any problems at .035?

 

I wouldn't waste my time reading your post if it was right


Iridiums only in an LNF.

Period.

Unless you like misfiring...ask me how I know

 

Ok, so I put the new spark plugs in (AutoLite XP iridiums) gapped at .035. The issue I was having were pretty beefy backfires in 1st, sometimes 2nd etc.


Another thing, wasn't it said by someome that the stock spark plugs on a SS/TC are AutoLite? I pulled out ACDelco spark plugs. She running real good right now with the problem going away. I would like to see if I could go lower

 

Mine were ACdelco's when i checked the gap on em the other night. I've been hitting a wall around 3K rpm , feels like it falls on its face so i dropped the gap to .030 just to test. I haven't notice any ill effect from it , and the other night coming home from the track it felt the best it's ever been..... but it was getting cold out 55-60. I'm going to open em up to .032 and just see how it does. On my SS/SC i tested every gap from .030 to .040 and settled on .033 as thats what my car liked the best.

If my car had the same mods as yours i'd prolly try .030 and see how it reacts. The only thing it costs ya is time.