OK, I'm afraid this is another "what LT header" thread. The difference is this- I want stainless headers and a catted Y-pipe. 04 ECSB 2WD. I'm planning on having a muffler shop do the header install and I know they won't delete the cats. I don't care if I buy a pre-made catted Y or I have these local guys fab one up. I do want something that fits right.

So does anybody have suggestions for stainless headers that work with a catted Y? Under truck pics would be great, because I don't understand how the cats will fit behind LT header flanges. Seems tight ahead of the tranny X-member.

Engine will be a rebuilt 5.3 with 10:1 comp, 241s and mild cam.

 

American Racing Headers are probably the best fitting stainless with catted Y but they are also about the most expensive too. Look them up to see pics of how the cats will fit with their system.

It would be hard to fit universal cats behind the headers and before the trans cross member for sure, especially if you go with 3" pipe to build the Y.

You could do what I plan on doing and run a cat-less Y then run a single cat where the Y comes together and go into the muffler after the cat. This way there is more room and you can always have a "test pipe" made to replace the cat on days you want to go to the track.

Edit: Just saw a set of Kooks LT's and catted Y for sale in the Classified section. May want to check them out as well.....

 

Do most guys with headers run a ORY? I guess if you're not in cali or NY you just chuck the converters and have the back 02s tuned out?

 

Yup thats what we do

 

In Texas they are supposed to do a "visual inspection" for cats I believe but on OBDII vehicles as long as the check engine light is not on your good. So, yes, most people run an ORY or they will have a test pipe they can run and put the cat in for inspection.

 

Just be warned about the el cheapo ebay headers. They work and fit ok but they suck when it comes to the small stuff. Such as O2 bungs in the wrong spots connections not fitting tight odd ball donut gasket size the list goes on...

 

Even some of the mid level headers have these problems.