Going to California...
I have installed the CARB legal shorties and stock cats. I also have a 3" catback.
The stock ypipe is appealing to me because of its great ground clearance.
So my questions are:
Would I gain anything by moving to an aftermarket YPipe?
Is there an aftermarket YPipe that offers clearance similar to stock?

Edit:
Money is not an issue here whatsoever...unless it is made of platinum or the ilk!

I'm not totally sure, but I believe that the cats cannot be moved from their stock location. atleast thats what i think i've read for cali.

the stock Y-pipe is a compermise ,clearence ,cost ,fit.a good shop can make a custom exhaust or Y-pipe the flows great and fits.

You're right. Can't move 'em. C.A.R.B. legal basically means it will pass. And why he has the stock cats (Same stuff I'm having to do). I am thinking of the Headman YPipe myself, but now I'm worried about clearance. It would be nice to clear like the stock pipe! God damnit. More stuff to think about.

The prevailing LS1tech wisdom is that you won't gain anything. Same for shorty headers.

That being said, you may gain some theoretical satisfaction knowing that you have a nice flowing dual 2.5 Y. SLP and Dynomax make them and fitment is said to be good. Check WS6 Store if you think it's worth it to drop a couple hundred on one.

I hate to steal this thread, but...
The stock collector on the Y is 2.5, isn't it? I want at least the pipes to collect into a 3" to match the catback. Is that foolish?

I'm in the same "Going to California" boat.

Edit:
I am in the complete opposite boat as 74 when it comes to cash!

My condolences

And mine to you for not knowing that the same is coming to a neighborhood near you!
16 states have adopted California laws, and the remaining 33 will follow by 2016 when the Federal Government enacts California emissions standards. All of this backed by GM as a way to get bailout funds in bankruptcy; which they turned around and got money from Canada to keep jobs THERE instead of the U.S. and paid off the U.S. with Canada's job money!

Besides, San Diego is beautiful and I'll run YOU down anytime anywhere.

Sorry I hijacked and probably tanked this thread for you "74"

Only thing I see regarding Commiefornia, sorry, California emissions standards in every state has to do with new cars sold in 2016 and later. I would imagine the 30mpg requirement for trucks is a sticking point; once comrade messiah is out of office, I'd bet the auto industry will probably petition to have the standards changed.

To the OP: you might pick up a couple horses using a y-pipe with a better merge, but doubtful that it would be a whole lot.

Im running TSP's 224R, stock manifolds/cats, with an SLP Y and loudmouth. Its nice and tight up to the bottom of the car. I dont know how much I gained with the Y, because i swapped a bunch of parts at the same time though. It clears my UMI tunnel mount torque arm with driveshaft loop perfectly.

Thanks for the responses battousai, garygnu, RevGTO and NCR_SPDS.
Transsam, I may share some of your beliefs, but stir the pot somewhere else!
X-ray and Element, you are useless. I can't wait to get to Cali, and how Sean Hannity, Rush Limbaugh, and Glenn Beck Communism calling B.S. and stop post whoring.

Thanks for the good info, I might as well try to pull what I can out of the exhaust.
Thanks again.

Or completely ignore the fact that I actually replied to your question, that's cool.

Thats really all you can do out here. Do you still have your AIR and EGR, if your car had it? Some smog shops can be super picky about that stuff.

The setup on my 01 WS.6 was: Lid, P&P TB, stock LS6 Intake, TSP 224R, Comp 918s, Stock untouched manifolds/cats, SLP Y, LM1, Performabuilt stall and Level 2 60e, with 3.73s.

It dyno'd 350rwhp/352rwtq on a Dynapack dyno, with noticable slip through the converter. Its also completely smoggable. It passed easily.

I kept all of the factory stuff (my son was convinced it was worth it). We got an SLP LS6 intake to add EGR. I am pretty undecided on the cam, but I have a lot of people trying to push me to the TSP 224R - ALL of our engine components are from TSP; I'm a fan.
Thank you for the help sir!

If any of you guys are near San Diego i will sell you this for $70 it should be worth about 10 horsepower maybe more if your modded. It is a pretty simple 20min swap.

tottaly true..the stock y pipe isnt the only resitriction. i felt some gain by removing cats which wont help you. id stick to stock piping. just get a reducer to fit your 3" catback.