5.3 to 6.2 OEM Exhaust Swap

[Bohanan23]

Hey guys, just purchased my first "new" truck last week for my 22nd birthday. I've already caught the bug for upgrades. I am picking up a factory 6.2 exhaust on Sunday. As far as bolting up to the factory y-pipe, will I have any issues? I wouldn't think so since both are factory exhausts and for same truck model, but it's better to ask now than have the stock exhaust already off and run into problems. I know I should net a little extra power, but I am also chopping off the flapper valve and replacing the stock muffler with a 3.5" Borla XR-1 and leaving the resonator, for now. Future plans will be 1 7/8 headers and y pipe. Anybody have a similar setup with the 5.3's? As far as swapping over to the 3.5" exhaust? I know a lot of aftermarket exhausts are 3.5" to 4" but are pretty pricey. I think for spending $100 on the factory exhaust, $200 for muffler, muffler/valve chopped off, it should be a decent upgrade

[2003 SSEi]

I believe they are different.  I thought the exhaust diameter was larger on the 6.2., and the ball connector wouldn't fit.  

 

you are going to want a replacement Ball Clamp, your most likely going to have cut the one that is on the truck off.  

[Bohanan23]

I know the diameter is different, I just wasn't sure on the connection if they were different to mat up to the existing y-pipe. I haven't looked but I figured it wouldn't be an issue. I will check it out though!

[newdude]

Yes they are different. 

 

The converter y-pipe and the exhaust are 6.2 only, and the 5.3 stuff is 5.3 only for the factory equipment.  The ball socket on the back of the 6.2 converter is larger to accommodate the larger piping, and the clamp is larger as well.  GM uses a ball/socket joining method between the cat and the exhaust, with a somewhat spherical clamp.     

 

You'd have to get the cat y-pipe as well to use the factory 6.2 exhaust. 

 

 

Edited March 22, 2019 by newdude

[Lsgun1]

If you are getting headers just add the 6.2 exhaust then so you can have it bolt right up.

[Bohanan23]

I am getting long tubes and y pipe eventually, for the time being I was going to throw on the 6.2 exhaust with aftermarket muffler for mean time. I didn't realize the ball joint. So I will hold onto the exhaust and wait until I upgrade to y pipe and headers!

[SILVER SLED]

...or just have an exhaust shop modify the y-pipe (since your getting rid of that eventually anyway) to fit the 6.2 catback.  Shouldn't take much.

[Bohanan23]

True! I'll see what they can do. I just don't want to spend too much on it since it wont be long before I remove the stock header and y pipe! Thanks for the tips

[pewterliftedz]

The 2 cat backs are not compatible!

The 6.2 and 5.3 exhaust are the same after the flapper pretty much anyways.  The 6.2 exhaust goes down to 2.75" for the resonator and tail pipe, there is no reason to swap your 5.3 exhaust for a 6.2, the only thing that is bigger is the muffler and intermediate pipe, you're wasting your time and money.  Just slap a muffler on your current exhaust and delete the flapper at the same time.

[qwank]

I have a picture of both for reference 

 

[Bohanan23]

Well, update. Picked up the 6.2 exhaust over the weekend. Going to go ahead and pull the trigger on longtubes and y pipe from Speed Engineering today. Going to get everything installed and then have a 3.5" Sportsman Borla XR1 installed. Going to leave resonator on there to keep it a little more quiet. Should have everything installed and tuned within a month or so!

[sammo84]

On 3/24/2019 at 6:24 PM, qwank said:

I have a picture of both for reference 

 

What is the diameter size of that socket for the 5.3l?

[sammo84]

What size male ball goes into the female socket on the 5.3l?

The long tube headers kit I got doesn't have the connector pipe from the long tube headers  to this expansion pipe.