X & Y pipes vs Straight pipes

[Hood]

My stock 340 has straight pipes running from the headers to the mufflers mounted in front of the axle. Then tailpipes over the axle to the rear valance tips. Are there any benefits from either an X or Y pipe installation?  My mufflers have lasted 26 years and I will be replacing them this spring.  Now would be the time to consider all options.  Opinions welcomed, thanks!

[jimynick]

The stock size of 2.25" is something that I think should go to 2.5" unless you've got some hellacious motor. While there's a few suppliers, as I've looked at doing this myself, looking for bang for a buck, I found that Pypes offers a stainless system that Summit sells for $650, and I saw it for sale at Carlisle 2 years ago for just under $500, so you should shop around if you choose to go that way. Hope that helps. 

[Chryco Psycho]

Even the factory used H pipes to balance pressure from side to side so yes they help .
X pipes are the most efficient but do change the sound , so I would recommend using either H or X pipes both will help with efficiency .

[Spikedog08]

I have both, certainly recommend either setup and Chryco has stated above.  But honestly don't realize any difference in the 2 setups . . 

[RUNCHARGER]

Not sure you'll notice any differrence with your stock 340. They also can make transmission maintenance more difficult.

[dodj]

I went with a Magnaflow x-pipe system. The reason? The sound. 

I don't think you will notice any performance increase with your butt meter.

[Hood]

I decided to keep my straight pipes the way they were and had a pair of Flowmaster FX 's installed last week.  Eventhough they sound more aggressive than I anticipated, I am very happy with the outcome.

[70/6chall]

Ok guys talking "H" and "X" pipe exhaust system crossovers. Different set-up but still the same concept. When I decided to open up my exhaust system on my Slant6 Challenger I did this.
I added Hooker headers 3 into 1 so off the collectors I run aluminized 2.25" pipe with an "H" pipe crossover. Remember the 6 has the exhaust running down the drivers side of the car to the back, so the crossover pipe doesn't have a great distance to cover. Then it's to the back where one pipe goes into a glass pack muffler then to the passengers side of gas tank then to a chrome Cuda style tip. The drivers side exhaust goes pretty much straight back through another glass pack passes drivers side of gas tank to another Cuda style chrome tip. I notice a mellower sound at back and at idle sounds like a small block. I like the sound exhaust seems to scavenge better. A six with duals.     Al