Gibson GP129S-C Ceramic Coated Performance Header

Small HP Gains between 3000-5600 RPM. Look great in the truck and add a low rumble/throaty exhaust note. Little pricey but sounds great.

I'm an ASE Master Tech and have done lots of work on countless vehicles over the years, but I'd never really strayed far from factory parts, and the issues I've had with these headers is reminding me why I prefer factory.First off, the headers look fantastic. I installed them on my 2011 GMC Sierra with the 5.3 LS V8 while doing an AFM delete (I figured since the manifolds were coming off anyway, might as well throw these on as I had been eyeing them for awhile.)When the headers first arrived, I was unimpressed with the gasket surfaces (where the headers meet the cylinder head.) They were very rough and poorly machined. I had little confidence in their ability to properly seal. I had a machinist friend of mine mill the gasket surfaces perfectly flat and figured I'd be good.The headers seal nicely against the cylinder heads (probably thanks to my friends' machine work,) but for the life of me I CANNOT get the flanges (which attach to the y-pipe) to properly seal. They just BARELY leak under moderate acceleration but it's SUPER ANNOYING. The flanges are surrounded by rounded out areas of the firewall and the small "ticks" they emit echo like crazy, making it sound louder than it really is.I have tried again and again to get this to seal up with different gaskets, etc. I even considered welding in a flex pipe in the center of the y-pipe to try to take some tension off the flanges, but ultimately decided against it. Now, after so many times on and off with each attempt at repair, the passenger side ring flange is beginning to warp, making the leak worse.For now I'm living with it, as I've run out of time to mess with these things. But next year, I'll probably be taking these off and reinstalling the stock manifolds. I just can't stand the leaks.I will also say that I did actually notice an improvement in low end torque. The truck no longer has to downshift as often when passing or climbing hills. The intake sound also decreased, leading me to believe the engine is in fact breathing better with these on. However, the noise from the leaky flanges just negates these positives for me. Not very happy, wouldn't do this again.

This is the Header I have been looking for my 2005 Tahoe for some times, due to the price I want to paid, it worth the wait, this header fits well, I am not a Gibson"s fan, but the quality I see on this headers are very well done. The instruction on removing the driver side exhaust manifold is just a general description. As the beginning of the instruction stated ( general mechanic's knowledge, and a reasonable degree of experience is required ) . On my Z71 model, the exhaust manifold has to come out from the top, due to the transfer case drive shaft is in its way. After installed the header, it match the angel of the stock exhaust very well, if you do it right. I install this header after the CAI was installed, I get 1.5 mpg better than before, on top of the 1 mpg from the CAI, I think it well worth all the work I have done to the replacement.

Bought these for a 2008 Tahoe LTZ 5.3 V8. Called gibson they verified I bought the correct set. It does not line up. Had 2 separate shops work together to try to get these to work, they would not fit. If you do what they say and tighten middle bolts on header and try to put a bolt in the front hole....the back won't line up. If you put it in the back the front won't line up. Nothing is in the way, nothing is resting on it, it is free from obstructions. It's literally not fitting because the craftsmanship is was waaaaay off on this particular header we bought. This may be an isolated incident, however I wasn't happy with that. I will say the finish on it was really nice which is why I'm giving it 2 stars instead of 1. It was also packed nicely.Amazon customer service was amazing.

Installed and functioning great. I had 5 broken exhaust manifold bolts which is a very common issue on Chevy Silverados (mine is a 2008 1500). This required removal of the stock manifolds. I took the opportunity to install these in their place. They do make a considerable amount more exhaust noise, but that is to be expected on thinner tubing of headers. Mileage boost and torque increase felt.

works well ,looks pretty , fits perfect on my 08 Silverado wish they were cheaper but I only wanted to do this job once and according to the reviews and I totally agree Gibson makes high quality products

Good

Great shipping great price excellent product couldn’t be happier

They were exactly what I expected and fit my 2013 Chevy Silverado 5.3 perfectly .

These headers are a must have. Install time was about 3 hours. Truck sounds great. Best of all I picked up 2-3 mpg!

WORKS FINE

So far there hasnt been any issues. Headers bolted on easy. The only problem was conecting to the Y pipe. Alignment was off a bit and bolted up pretty tough. Had to grind down the flanges to make and tighter fit.

Great fit, easy bolt on. Make sure you have different size extensions, and swivel joint socket.

It is a good quality product!!

Installation was easy, fit like a glove, pasted SMOG with no problems. Would highly recommend using this product.