3in ORY into 2.5in stock catback?
 

how do u do this, i am doing my header install myself and i was wondering how do i get everything to fit together?

You can get a reducer at most parts stores I think.

It should not be a problem. Because I had that set up for a while. Your headers will replace the stock headers and cats. You will most likely remove the stock Y pipe and use a 3 inch Y with or with out cats. If you still have your stock cat back it will connect right up to the Y pipe.

It kills performance so most people don't do this. ;)

If you are planning to keep the stock exhuast, I'd go right into a 3" cutout and reduce after that. That way when you need it, you get the benefit of your free flowing headers.

I will be running the stock catback with Lt's and ory. I plan on making the i-pipe slip into the y. And i have a cutout in the i-pipe

that is also what i am doin i am just makin sure it will fit fine.

same here, but I would think twice about putting the cut-out in the I pipe. It won't do you much good to go from 3" Y to 2.5" I to 3" cutout. I'm gonna put my cutout in my Y pipe.

You can always get a couple of feet of 3" pipe and run it from the y-pipe to where you put your cutout, then just weld the factory I-pipe back on after the cutout.

or just get a catback

Maybe I wasn't clear; but we're on the same page. The Y-pipe goes into the cut-out and and then reduces down to the I-pipe. Consider putting a QTP in there, and maybe a turndown if it would fit.

I like having the cutout further back, so I'd go to 3.5" I-pipe, move the cut-out closer to the axle and then use 2 reducers to neck down and go over the axle.