What are the specs when ordering a new muffler?

I was looking at ordering a flowmaster 40 series delta flow for my 2005 2.7 tacoma. What should I select as the inlet and outlet pipe size? Should it be Center inlet ant Center outlet? Any thoughts or common on this muffler. Will I compromise MPG? Im looking for power increase, acceleration increase if possible. Any input is appreciated

 

You won't see much to any performance gains from swapping a muffler. The most you're going to notice is a sound change.
On the 4.0L the pipe size is 2.25" and the muffler has a center inlet and offset outlet.

 

the 2.7 is also 2.25 ( i am going to do the same thing you are) i am also going to put on a 40 delta flow, this week i hope if i have time.

 

The guy at the muffler shop convinced me on this muffler called dt? I've never heard of it . So I ended up getting it for a good price . I regret it, It spunds like a ricer, my acceleration is slower, I'm definately dissapointed.

 

Doug Thorley?

 

well rip the thing off then and go back to shop and tell them the deal.

 

I'm waiting on my pro dry filter to do the intake mid, if I don't see any improvements, that crap is going back!