I was thinking of using NGK TR6's. I have a 388 ci LT1 that has a .584/.579 cam, fully modded with ported heads and 11.7:1 compression. What plugs should I run? I was thinking NGK TR6's but what gap do you guys recommend? I won't be running NOS since I have hyper pistons. Just let me know if you recommend different plugs. Also in mind are NEW! Autolite XP Iridium spark plugs which provide the biggest spark and Iridium is suppose to be the best thing out. THanks

 

hmm, well mines a 383, around same lift, 11.21:1 comp, and I used AC Delco rapidfires. No problems there...

 

What do yall think about the TR6's, will they work good? Im getting them really cheap

 

I use tr-6's on my 383, 11.25 to 1 comp, they work fine.

 

Autolite 103's are good for that set up...post up if anyone has heard different

 

im running NGK R5671a-7 or also known as 4091 recommended by Llyod for my 396 12.5 comp motor

 

Where the H$ll did you buy them

 

summit or jegs has them summit goes by the 4091 number jegs goes by
r5671a-7 same exact plug i have heard of some people getting them at autozone but i cant tell you myself got mine from summit gap em at .035-.040

 

I use the R5671a-7 in my 383 gapped at .035". I bought them from Advance Auto, using the part #4091. They are a special order though, but it only took one day to get them.

 

How do the TR6 Iridium's stack up against Bosch Platinum +4's?

 

I use the NGKTR55's witn no NOS. The NGKTR6's are a colder plug. If you are not going to use NOS then the TR55's are a better plug for your application.
HVY SS

 

Irridium would be more a longevity thing than any other "benifit" and the multiple electrode stuff is sales gimicks, ever notice none of the head or engine guys recommend any of that stuff?

 

I would probably try one step colder plug then the TR6 for your application. The rule of thumb if I remember correctly is for every increase of 75-100HP you go one step colder.