spark plugs?

[13's or bust]

which plugs do you guys run? im currently running autolite double iridiums...idk if theyre good or not. can someone give me some direction on what plugs i should run or what plugs you guys have had luck with....its also a 3500 but i dont think that makes a difference..thanks 13's or bust...also what plug gap do you have your plugs at? i put mine at 55, instead of stock 60

[DTMAce]

Iridium or stock types will be fine. Most people on here have not really seen a difference or at least a noticeable difference regardless what plugs they use. I just stick with stock replacements, they usually do just fine. Only thing with using the iridium is they last longer. That's about it.

[MY91GT(Z)]

i like my ac delco rapid fires and gap them at .053 my cars have always ran great. but i use reg autolites 104s in the gtps but thats cuz they are colder range for the car

[Kris GTwhat?]

I use ngk iridiums

[Asylum]

Delco iridiums ARE NGK. Work great!

[Cliff8928]

I agree, the ACDelco 41-101 is FTW. My 3400 has the platinums in it though, the iridiums weren't out yet when i put them in.

[SuzukiGhostRider]

Iridium's are where it's at. They're not just a "longer lasting" plug either. They burn more efficiently with a sharper , stronger spark. Most people will notice increased throttle response and some a slight bump in MPG's.

[Chad91GTZ]

I run AC Delco Iridiums, painstakingly indexed. Index your plugs for a 5% HP increase.

[berettaboi]

whats the trick to indexing? can you grab more metal washers off of old spark plugs? (rather than over tightening them too much)

[Chad91GTZ]

I typically have to buy between 8 and ten plugs, they all have the gap in a different location from the starter thread. I put them in the car, run it for a bit, then remove them to check where the flame travel is. When i find the right ones i just tighten them back to spec. No over tightening. When you add washers you change the plug reach, and undo any benifits of indexing.

Which is why a lot of people think indexing is a joke. But ive proven its a significant enough increase to spend time on, when its done correctly.

[13's or bust]

i think imma switch out to the delco iridiums...im currently using autolite double iridium or something like that they were like 5.30 something a piece. theyre doing fine i think i have no idea until i take them out. thanks guys, imma do the delco iridiums.

[KFLO 93 GT]

The reason I think that indexing is tomfoolery, is because you'll get a different answer on which way to index it depending on who you ask.

I know how I'd arrange mine if I took the time, but at $7 a pop I only get 6 iridiums at a time.



41-101 ftfw.

[Chad91GTZ]

Theres only one way in my book. Put the gap towards where the flame starts.

[SuzukiGhostRider]

I don't understand the hype over buying "AC Delco brand". Why? To enjoy paying inflated prices for a name? Autolite Iridium's are what I run,and they're a little under $4 a plug my cost, $5 something usually. Just as good,if not better, than AC Delco's brand of Iridium.

I WILL admit GM's ignition system (for the most part) is hard to match or beat aftermarket, but plugs? Please...... They're not the king of the mountain there.

[KFLO 93 GT]

Factory part number. If it wasn't the Delco it'd get the NGK Iridium. Same price difference around here.

No hype, just proven performance.

Nothing against Autolites, I run Autolite coppers in my L36.