From what I know I think the oval bodied are chambered and the round body are straight through. I've seen the ricers use the round ones, they're too loud for my ears.

 

In some cases that is true, however this is not one of those cases... My xr-1 was oval and you could stick you hand straight through it. The XR-1's are a straight through design regardless of which version you get.

Now oval or round? Round will be louder, oval will be deeper. Casing size, shorter will be louder, longer will be more mellow. So if you want a loud deep tone, go with a shorter oval, if you just want plain LOUD go with the round and shortest casing you can get. I beleive mine is about mid length between what they have available. Didn't feel like going to short and didn't want it round. It was the right choice for me...

 

i got a BORLA exhaust on my 4.7 dak and sounds awesome. it has a low growl at low rpms and a "wow, what the hell is that" sound at wot. people look to see what it is. i like when go to a gas station and people start asking about the truck! right now i'm using my phone but when i get home from work i'll post a video clip of the sound!!

 

sorry! double posting.. stupid "smart"phone. jeez....

 

Yeah I'll probably like the deeper tone so I think an oval shaped muffler will be the way to go. As for length I still want to be heard to I'll probably go with a shorter case size..

 

truckin you got spanked by a quad....j/k man sounds great had to mess with yah....

 

Here is the video af my Borla exhaust:

http://s4.photobucket.com/albums/y10...t=MOV00463.flv

 

Me and him are in a "war" to be the fastest truck in our little group since the guy running in the 12's id out after he totaled his truck. Maori is in the running as well and as soon as he gets it to stick its going to be a beast of a truck...