I'm also doing a magnaflow muffler only swap. Any know which part # people are using? And what it sounds like. I was gonna go with a 6"inch round 14 ' long keep my stock pipes, just add stainless tip. Sounds like an easy swap. Hope i get the sound i want. That's also a good tip to keep the stock system intact and have them weld up the tailpipe, might be worth the money. 06 screw 4x4 with 5.4

 

Believe it or not(and I actually found this funny), there are national chain shops removing stock muffler/tailpipe assemblies, keeping them in the back if the customer doesn't ask for it back, then selling it out the back of the door for hundreds of dollars. That's right, not just a few bucks, but hundreds. I know b/c I inquired from a garage(no names) about getting one(thinking they would just give it to me). They said, "Sure, for couple hundred dollars". What a crock of crap.

 

why not do like what im about to do.. my 07 is a lease.. i plan on buying it out at the end of the 2 years.. on EBAY there is a guy selling full polished stainless 2.5" cat-back for our 04-07 trucks, the guy tells me that it is a deep aggressive tone, and the muffler they use is a free flow design, for $289 and only $18 shipped i think its a pretty good deal. and its all bolt on no modifications needed.. just my .02

 

I ordered a Magnaflow 12256 form Performancepeddler.com. IM still waiting on it.

 

If you want louder you can dump it at the axle. I have the stock pipe to the 40series flowmaster and out the muffler I have a chrome downtip from Midas that the guy sold to me for $10. It's much louder than having the exhaust exit the stock location and since I have a welder it only cost me the muffler and tip. The only thing I suggest is adding a bracket at the rear of the muffler to keep that from flexing over every bump.
Now, it does drone a lot more than it did coming out the back and I am thinking of going with a different muffler in the future to get rid of the drone but it hasn't really annoyed me yet cause I just turn up the radio
If you want really loud install or have a shop install a cutout before the muffler and you can even get electric cutouts so you just have to flip a switch to open the exhaust up! Though, it's probably illegal in 45 states so just open it up at the track