Thanks for the info, guys. Yall are awesome. Are there any write ups on here about the coolant bypass mod with pictures? I did a search with no luck.

 

you gap at 55 and you will get random missfore code. Been there done that.
Why do you think the Chevy/GMC TSB says 40 instead of 60 or 55....

TR6's are a "Safer" plug to run in hot weather with crap gas. Run some hot plugs while towing in 100* heat. let me know how mutch clatter you hear...
Shure run TR55's and get alil more power from a hotter spark, but you will detonate more.

I choose safety over power in my DD anyday of the week.

As soon as you start removing that TB you will instantly see how to do the bypass mod.
You can cap or leave open the tubes on the TB. your choice.

 

https://www.performancetrucks.net/fo...d.php?t=456548

 

Yawn, Anyways. Not going to clutter OP's thread anymore with a plug debate.
I will run what I want, you run your thing.

Regaurdless, if he runs Whatever Plug type at 55 or 60 it WILL RANDOM MISSFIRE!
This is very well documented on EVERY GMC/Chevy forum on the web.
There is even a TSB out there somehwre detailing this. TSB = Technical Service Bullitin.


GL, on your mods and cleaning OP..

 

I'd like to see this "documentation". I can't find anything about this.

 

daily driver? buy the ac delco replacements from autozone! Get the gap information from their computer system, gap the new plugs and install them. Shouldn't take more than an hour of time! Wires = simple!

Edit: I've gapped all my plugs at 0.035 and each time everything works perfectly!

Edit: Being that you live in TN and the winter it does get some what colder - I would shy away from the TB bypass. I've done it on my "SS" truck but that only gets driven in the summer months.

 

Thought this was interesting: http://www.custom-car.us/ignition/spark-plug/gap.aspx

 

this is exactly what I have told!

 

I am about 3 hours from the OP and there is nothing listed here I couldn't do in my sleep. Hollar if you need help.

 

So, what's the verdict on the gap here? My truck is my DD, and it does get quite cold here in the winter. Not a track machine, more of a red-light warrior. MPGs are important to me, too.