Quote Originally Posted by 04boostedindyss View Post
How are 104s to cold? My bro has 103s in his l32 regal gs and it runs awesome and pulls like a raped ape, and when he went with drilled tstat and switched to 103s over 104s he was able to kill some kr he was getting
Personally preference, just noticed I pulled harder with 605s cause my tune is set up that way, but going to cold on plugs can induce knock as well, also notice better fuel with 605s over 104s. Every motor is different.

So I say stick to 605s until you are on a 3.4 and then go for 104s.