well, its good to hear someone who has tired them all, and had the same results with all three. Sounds like I will prolly get platniums again then, as it wasn't their fault that they possibly carbon tracked. Might try a slightly smaller gap though.
Any other ideas?

 

Heads cam blower this that, Have had it all done to my car. Just need to pick the proper heat range if you are running an adder but I just run the copper ones and change them often since I like to see what is going on with them.

No differences, I do gap them a bit tighter than .50 though.

If I had a stock car I would keep them at .50 just since it does not make a difference to much.

 

well, I went with the AC delco rapid fires this time. They are the number 14, with a gap of .060. We will see how they perform. I took the old plugs to the dealership, and they found a bit of carbon tracking on a couple plugs. So, hopefully I will be good as new again shortly! I will let ya know!

 

Did they show ya the tracking?

 

yup, there was a black line at the base of one of the plugs, it stuck out pretty good. Why do you ask? It looks almost like someone drew in a black marker. That is what the carbon track looks like.

 

It's generally so light that it get's wiped off when removing the plugs.It would be like a very light pencil line on the porcelin. If it was in the gap at the base between the metal and porcelin it was a defective plug from the git go. That is why I use the three major American brands.

 

and the three american brands are??? GM isn't a american brand? hmm, news to me.

 

AC Delco,Autolite,Champion. If that was what ya were running it was still defective.
Have had a lot of problems in the past with platinum plugs of any brand,but that's just me. Can't get um to run right. '96 and down didn't come from the factory with them according to my factory manual so ya might have to not run them.

 

What kind of HP levels is your "stroker" (that's all you've told us about the engine) making? Generally, as HP level goes up, you want to start to move down to a colder plug. I run the AutoLite 104's (1 step colder than stock) gapped at 0.040". That's on an engine making 500 flywheel HP on 10.8:1 compression. I've also used the AutoLite 103's (2 steps colder than stock) gapped at 0.035" when I spray the 125-150 shot. Back in the days of the bolt-on stocker and a 125-shot, it liked the NGK TR6's.

I would think with any sort of decent HP level, you'd want to think about going colder than stock, and narrowing the gap a bit.

The stock LT1 compression ratio is quoted by various sources as both 10.4:1 and 10.5:1.

 

oh sorry fred. I thought I was around 450 hp, as that is what the engine builder told me, but I seriously doubt its even that close! I only have mid length headers, mild port job on heads and intake, 52mm tb, 42 lb injectors, and hotcam kit. I know, everyone will laugh, but my engine builder said I should be pushin 450 flyweel hp. my guess is prolly closer to 350. but, like I said, there are two guys that I work with that race NHRA bracket racing, and their 650+ engines run rapidfires. So I thought I would give them a shot, as they are 8 dollars a plug, and I got them for 3.77 my cost at the dealership. When GM is that cheap, WHY NOT? ya know? So, any more questions?