ima be saving money for a LQ9 as soon as i get my posi and 4.10's installed this week, im ashamed to list the exhaust i have now, lets just say it rhymes with.........rollmaster.........ya.....thats it........... anyways, i am also going to redue my exhaust but i dont know if i should just do 2.5 piping all the way through with the 6.0 or should i wait till i get the 6.0 and do 3'' all the way through, but i dont know if it will be overkill for it, since it only puts out 345, what should i do?

 

No not at all. I have had 3" on my 4.8 for a while now. So I would think that it woudl be a good fit for the LQ9

 

so with 3'' all the way from the headers back would be fine? ive heard a few people say that 3'' is overkill unless ur pushing like 450hp and up

 

technically 2.5" duals work just fine until you hit the 500's, but there's nothing wrong at all with 3". You might get a little deeper sound, and you'll never have to go back to it.

 

I'm gonna be running dual 2.5's when I eventually do my LQ9, which will be mildly cammed with headwork. On a stock LQ9, I'd think that dual 3" would be too much, just my .02

 

I think you should just go all and dual 4" exhaust Jk I would do the 3" just in cause you do FI or decide to turn the power you will have the exhaust upgrade done....

 

Im going to be using a 3inch ORY pipe on my 418 which will needless to say I will be making more than 500hp on motor and closer to 800 on the gas. I had dual 2.5" on my truck with the 5.3 and I didnt notice any loss. 2.5 is what I would do if it was me you wont be making 500 anytime soon from the sounds of it and IMO dual 2.5 is good for more than 500.

 

if you plan on staying n/a i'd suggest...
3"single in/out or 2.5" true duals w/ x-pipe.

 

I am going 3" on my LQ9 with a large cam, stage 2 heads and a few others. The LQ4 comes with 3" from the factory.

 

actually i'm going to be trying to utilize as much of the stock 2 3/4" pipe as i can. Probably the stock Y pipe cut, a X pipe put in, then 2 2.5" bullets, then the stock piping.