So I am getting ready to drop in my newly rebuilt L98 with mild performance cam and everything else stock. I paid dearly (actually this is a really good price) for Denso 90% Iridiums in the hope with as few miles as I will put on this car each year I will never need to change the plugs. Anyone else have experience with these plugs? The engine will get a custom tune right away to get everything right ASAP.

Product: https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1

 

Basic bitch Bosch Platinums will go longer than you'll want to leave them. If you're paying more than $2/plug you're flushing money.

 

Yeah, but I hate changing the plugs. It's beyond hate. Even if $6 more per plug gives me a 10% more chance of avoiding it over the $2 platinums, it's money well spent.

 

What's the service interval on basic platinum plugs? 100k+ miles? Pretty sure it's a non-issue.

 

Yup, ANY of the modern OEM-grade platinum (or even rarer metal) plugs will do just fine. AC Delco, Denso, NGK, Bosch, Autolite, Champion. Don't outsmart yourself. Look up what The Book says fits your car and go with it. Avoid "gimmick" plugs of ANY kind - E3, Bosch +4, there are plenty of others; they just kinda come and go they're hard to keep track of.

You'll find yourself changing them for reasons other than high miles anyway. You'll be surprised unfortunately. I wouldn't overthink it too much.

 

i agree with sofakingdom

 

plain old NGKs

Affordable, reliable, and forgiving. if you run a little too rich at idle they will clean up at upper RPMs and you can get them anywhere.

I changed mine after (4) racing seasons just to have fresh set since my overall tune is on the rich side. I saw no huge difference in performance between the used and fresh plugs which tell me my current tune is just fine.
I am going to clean the old ones in my blast cabinet, cut the straps back, re-gap them, and try them. Then I will see if the cut back straps provide any performance edge for me.

All the iridium schmeridium nonsense is just that.. A sales tactic to lighten your wallet. when I first bought my car I put in the split fire plugs... 27 years ago