yellowstang1994 said:But then switched to the platinum 25s and my car hates them.
HISSIN50 said:Hmmm, I have run colder plugs in many cars and never had issues. I guess others have read or had different experiences. Joe, why do iron heads matter (you piqued my interest)?
I would also never run a 25 on an aluminum head - where did that come from?VibrantRedGT said:I wouldn't run a 25 on an aluminum head is all. The aluminum can use a colder plug so in my opinion 24's should be better. I doubt a colder plug will benefit on iron heads since the heat is bottled up anyway. I have no proof other than my experience. With a power adder two range colder seem to work best.

HISSIN50 said:I would also never run a 25 on an aluminum head - where did that come from?
I thought we were talking about stock E7 heads in this thread (did I miss info saying otherwise?).
Running a colder plug on iron heads can help in my experience. You have not had luck with it and I have. I feel it is worth posting this so others can see differing opinions and know that it could be worthwhile.![]()
HISSIN50 said:Gotcha' Joe. Thanks for clarifying.
See Joe, you told me something I never knew - I did not think anyone even ran the 20-series plugs (like 24's) on alum heads. I did not think they even fit correctly; I thought it was 764's, 3924's, etc that folks used instead.