I have a 03 4wd avalanche 5.3 litre im curious as to what kinds of headers are available, and if they will make a performance difference or make the truck sound better, it has a flowmaster catback now, any imput apreciated thanks

 

Not positive who makes them for the Av, but I would assume the Pacesetters everyone uses for the Silverados would also work on the Av. Or you could try Thorleys.

As far as performance, yes, they'll definitely make a difference. Longtubes will give better mid-top end but may lose some torque, Tri-Y's should give more torque to mid but may lose a little off the top end. Not sure if you have one already, but be sure to compliment headers with a cold air intake kit.

 

I agree with Moze about the Pacesetters. But I don't agree wiht you on the loss of torque.

I put Pacesetter LT's on my truck just the other day, and now my low end torque is incredible!!! It has a lot more torque than it used too.

Long tubes are the best investment you can make for the heavy ol' Avalanche other than a good ol' Nelson Performance tune.

 

yep..awsome mod for the av...pacesetters will do it for ya...

 

did u have to get custom y pipe or anything to run the pace setters? and who on here has good prices on them thanks for the help

 

i have headers and Y that should match up plus i can tune your truck fool

 

trtturbo and speed engineering and have low prices on these headers and you dont have to do anything but put em on.....

 

I should have prefaced my comment with "from what I've read". I obviously haven't performed any independent tests so I'm just going on what I've heard and read, which is a long tube header will generally result in a slight loss of torque but will give great gains mid-top end.

Either way, everyone loves the Pacesetters, so I'd say they're a pretty safe buy.


Edit: now that I try to find information supporting what I just said, I can't. It's probably one of those things that you will always find claims that completely contradict each other. So I'd default to everyone opinions to use them. I got the Thorleys, but wonder if the LT's would have been a better choice (thinking 1/4 mile times here). Who knows....