Alright guys, I have to make a choice for exhaust pipe size and I would like your opinion. It will be true dual and exit behind the tires or under the bumper. Boost will not be an option here on Guam.

Here is a final list of engine mods.

LQ9/4l60E
42lb injectors
Ebay LT's with ORY
TBSS intake (is on the way)
212/218 low lift
K&N CAI

I have a brand new Magnaflow dual in/out 3" muffler (12469) that will be taking on the duty of quieting things down.

 

well ya already got the muffler, might as well go with the 3" duals, let your six liter exhale a bit...as far as exit location, i've always liked the look of one out each bumper corner at an angle

 

2.5" dual is just fine for your application. You can adapt the pipe to fit the larger 3" opening of the muffler with no problem.

 

2.5" is cheaper. If you don't want to adapt at the muffler, get the 3.0", which will be more expensive. You probably won't notice any difference between the two, as both setups are perfectly capable of supporting your setup.

 

Exhaust work on island is expensive no matter what. They are charging $400 for supplies and labor.

I think my Denali stock has dual 2.75 then y's after the muffler to a single.

My Truck is single 2.75 and I really think the exhaust is limiting the engine quite a bit. That Is why I was leaning towards the dual 3". I can go with dual 2.5's as that would probably be a little bit cheaper, I just dont want the exhaust to be an issue. Of course any size dual is better than what I have now.

Majority winning poll will be what I go with. Vote please.

 

400 for that is cheap, esp for duals... I think dual 3 might be over kill for that, but would leave you PLENTY of room to grow..

 

/\ What he said /\

People around here want me to pay $100 just to delete my muffler. For $400, you might as well get the 3-inch since you already have the muffler. That's cheaper than most catbacks; I wish labor was that cheap here.

 

Most people will vote 2.5" after reading your setup because you do not in any way need 3". I only voted 3" because you have the muffler already. Dual 3" can support 1000hp. You don't need that (or do you? ) but, as I said, you have the muffler already.

 

your headers only have 2 1/2" Collectors anyways?

 

so then when would 3'' piping be needed? I plan on getting my exhaust done soon also. i do however have a little bit more mods then him though. no turbo or charger though.