Here's the gaps (for stock to mildly modded NA trucks) that I've learned through my research...

Factory platinums = .060
NGK TR55's = .050-.055
Delco/NGK Iridiums = .045 I believe...pretty sure they come pre-gapped.

Platinum plugs should be good for about 60-80kish, TR55's for 15 to 24kish, and Iridiums for 80-100kish, depending on engine tune and a/f ratio and driving conditions.

As for wires, I like both the MSD's and the stockers.

 

NGK TR 55s N/A motors
NGK TR6s for blown or NOS applications
MSD wires
TAYLORS

 

Careful with pulling the wires off the plugs if you plan on using them again. They have a tendency to pull the wire out of the boot, so pull the boot, NOT the wire. You can spray a little WD40 on the plugs and let it soak for a few minutes to loosen them up. Make sure to use anti-seize on the new plugs' threads.

 

thanks,
i was trying to decide between the
TR55's
TR55-x's
or 12571164 – GM AC Delco Iridium spark plugs
but from your post the the tr55-x and the previous are the same.
would there be any real performance difference from the msd to stockers

 

Nope, but they look purty. Nobody has gotten on here and said anything about a SOTP difference and no dyno results indicating a different. The stock wires are not really a bottle neck in the first place and the power is only traveling a few inches anyway. I just replaced my wires with a stock set a got from a member with 20k miles on them for the cost of shipping.

 

Performance wise I've never noticed any difference at all on aftermarket wires. Now I will say that my LS based engines have always run a bit smoother on 8 or 9 MM wires compared to the stockers. I've always has a bit of a idle stumble with stock wires on all 3 of my LS trucks. I personally didn't care for the MSD's burned a wire up after 2 weeks of use and never touched a header. I personally like the JBA Power Cables, red is 8mm and blue is 9mm wires-but thats just me.

And when I was running the NGK TR55's I would always only get about 20K miles out of a set before they needed replacing.

 

I had knew that since the length was never a real factor, so guess i will order the stockers with the long list of other items i want.

i will probably order the stock ngk iridiums, i would like to get more then 20K out of them, is the part # i have listed correct?

 

are all LS series plug wires the same length?

 

No. Trucks are longer I was told. I had to wait when I ordered mine for that very reason.

 

Go For Msds And Ngks,i Just Did Mine At 140,000 And They Were Toasted