Okay read the sticky, sound advice. I'm looking for some performance upgrades for my 8.1L truck without rebuilding the thing or breaking the bank. I use my truck primarily as my hunting and tow rig so by "performance" I'm talking about pulling power. Of course any significant increase in MPG would be much welcome but not expected. My upgrade plans are;

41-993 plugs and wires (Done)
180 t-stat (Done)
K&N air intake kit
Exhaust, cat back only
Tune

Regarding the exhaust, the local performance muffler shop recommended just replacing the muffler with a Flowmaster 50 series dual 3" in, single 3.5" out, muffler.

Regarding the tune, I'd either look for a local shop or hook up with Blackbear or some of them recommended on here.

So.......any advice on the exhaust would be appreciated, as well as any advice on other options.

Getting it re-tuned will be the single biggest gain you can do. Make sure to run premium gas with the new tune also.
Dont waste your money on the K&N setup. I have ran my scanner on the truck at WOT while towing, and there is no intake restriction with the stock setup.

Hope that helps!

I love my K&N intake. You can deff. tell a difference with it

I ran that exact flowmaster setup (they offer a kit with the peice of pipe to hook into the factory tail pipe out of the single 3.5 inch outlet on the muffler, it just eliminates the factory y- pipe which just flows out one side anyway) on my 04 8100 truck, save your money, it sounded better but that was about the extent of it.

I like the K&N intake tube, but you have to be very careful when it comes times to re-oil the filter. I am still running the K&N tube, but changed filters to an AEM Brute Force (oil-less filter).

Get a tune, and you will love it. Talk with Justin at BlackBear. All you need is a laptop, and you can do it yourself. It is very easy to do.

i cut the muffler out and welded pipe in its place to use factory tail pipe and so it would have a lil backpressure dont think i gained or lost power but its a one of a kind sound
i like it

I like the K&N intake tube, but you have to be very careful when it comes times to re-oil the filter. I am still running the K&N tube, but changed filters to an AEM Brute Force (oil-less filter).

Get a tune, and you will love it. Talk with Justin at BlackBear. All you need is a laptop, and you can do it yourself. It is very easy to do.


I did the exact same thing, I was tired of the whole oiling process, id definately recommend going with a "dry" filter, especially if you are going to be off road much

Getting it re-tuned will be the single biggest gain you can do. Make sure to run premium gas with the new tune also.
Dont waste your money on the K&N setup. I have ran my scanner on the truck at WOT while towing, and there is no intake restriction with the stock setup.

Hope that helps!

What do you mean by "re-tuned"? Thanks

What do you mean by "re-tuned"? Thanks

I mean getting the PCM reflashed with a performance tune. It makes a huge difference on the 8.1L trucks. Contact Wait4me performance, Blackbear, Westers, etc. I think they only charge like $200 or less for a mail-order swap? I bought the software (HP Tuners) to do my own tuning, but it wasn't cheap at $600. Nice thing about the software though is that it works for tuning, scanning, and logging most all GM OBDII vehicles.
Go here to learn more
http://www.dieselplace.com/forum/forumdisplay.php?f=152

Tune will help out more than anything. 40+HP depending on tuner and octane.

if you ever looked at a k&n under a microscope you would throw it away get a wix heavy duty paper and change regulary your motor will like you in long run

I have cleaned a lot of dirt out of my intake from KnN's filtering., :rolleyes: These were clean well oiled. KnN expects you to run it dirty so it actually filters.

I went back to paper in EVERYTHING.

Yes K&N filters suck for normal purposes; but that's a whole nother topic. Dry paper is best!

I've done pretty much all the little mods to my 02 8.1, ac delco platinums at .045, taylor extreme 10.4 wires, 180t stat, new muffler, nelson custom tune and a few other things. They all made slight improvements and together they've made a pretty substantial gain in my opinion. I modified my air box and had a K&N filter which I threw away yesterday. I live on a dirt road and my I would have to clean my maf and throttle body every oil change, put in a cheap fram filter and it runs alot better. I would definitly stay away from any oiled filters. I'll also have a custom tuned tcm from socal diesel next week, we'll see what that does;)

Stainless works headers, CAI, tune, exhaust........for starters.

Okay, I'm agreeing that dry paper is best. Is it worth getting a cold air intake tube (can you even get one without the filter?) and putting on a paper filter. Does anyone make a paper or dry filter for aftermarket tube? On the CAI kits, is it the filter or the tube which is "supposedly" the performance enhancer?

I see some guys say they use Donaldson filters.......

If you're working the truck, towing heavy most every day.... Then there's really nothing to improve on..... It's a good solid work platform that's got to be tops so far as a gasoline powered HD truck/BOAT engine... If you're going racin'... Then that's a whole nutha thang...!!