Hi, my truck is a '99 2 door tahoe with the vortec 5.7 I am new to this site but spend a bit of time over on LS1tech.

I have tried a search but couldn't find exactly what I am looking for. I have an exhaust leak that I believe is due to the header gasket. I was planing to replace these and figured it would be a good time to throw on a set of headers since I will have to remove the manifolds anyways. I have found a couple of the old edelbrock headers that I may go with but have a few questions.

1. Has anyone noticed a gain in performance/sound/fuel economy with shorty headers? The stock "log" manifolds look pretty restrictive so hopefully there would be some gain. I know shorties aren't much of an improvement on LS engines, but they have much better manifolds from the factory from what I understand.

2. What header gaskets would you recommend? I know on LS engines most recommend stock GM MLS gaskets, so thats what I will likely get.

3. Does anyone make a Long Tube header that connects to the stock exhaust for these trucks? I have LT's on my car and I know they are the way to go, but don't want to pay to have a custom exhaust made and tune if I were to loose the cats.

4. How do they hold up to winters, I know they are coated but I am looking at used ones so I can't tell if they are stainless. Is there any way to tell this?

It looks like putting headers on will be very easy compared to putting LT's on my Firebird!


I often drive the truck on 3 hours trips so I don't want loud/droning exhaust, and I am thinking shorties will not increase the volume too much going to the stock exhaust. Note my truck has true duals in to the muffler, which is a dual in/single out.

Any recommendations would be great, it gets terrible gas mileage so any improvement there would be great (thinking a cheap CAI, and maybe replace the plugs and wires since it is about to roll over to 100K miles).

Thanks!

 

I answered your question at the other site, but here are some more pics of teh exhaust.

Here is teh Magnaflow direct fit, it has 2.5" pipe that is mandrel bent.


here is a Catco rear section for 3/4 ton apps

And its matching front section


Walker front


Walker rear


Magnaflow front


Magnaflow rear


Stock Vortec 350 1/2 ton and 3/4 Vortec 350 stock pipes




The 3/4 ton cats/exhaust is MUCh better.
All of the pictured exhausts, will bolt up to stock manifolds and shorty headers.

peace
Hog

 

Thank you for the help! I did see your response on the other site as well but was wondering what the "PE" mode is?

I like the idea of finding some of the 3/4 ton pipes at a junk yard I'll have to give that a try, but if not I will just be keeping it stock. One concern with that though it that I have a 2 door tahoe, so the muffler is in a different location?

Like I said I would like to do full exhaust/intake but it would get pretty spendy going with a fully stainless system and tune, I just had to replace the front hubs which wasn't cheap even doing it all myself. I get more enjoyment out of putting upgrades on my car, and would rather put that money towards a heads/cam swap. Plus the doors on my tahoe are rusting so I need to address that as well, other than that though the truck is in good shape.

My plan right now is to pick a set of used shorty headers, new gaskets (do you know the part number for GM MLS gaskets?) and run it. Maybe get a BB or PCM4Less tune down the road. I don't expect to gain much or even notice a difference but for $125 it can't hurt.