Yes the stock muffler is much bigger than a performance replacement, in fact about half the size. Stock piping is 2.5" and yes it would be worth it to do CAT back 3" piping.

Also get a muffler that is Center In/Offset Out. You will need to add an extension of pipe going from end of muffler to factory piping.

Also for a little more throaty sound you can cut the stock outlet part of the exhaust where it comes out of the rear and add a weld on tip that is in the range of 4" diameter tip.

It doesn't sound like much but it definitely does help it sound better from back of the vehicle.

 

Now your makin sense to me........

But if I owned the shop and did deals like that my drinkin *** would probably go under........

 

I hear ya man... But what a fun trip down it would be!