Will there be any mileage gains to look forward too??

Can I just replace the muffler or will an entire exhaust be in order?

I like the way my truck is (stock muffler)quiet so is there a better muffler that can be simular in quietness or are they just going to be loud?

The obvious question what are my options on brands that will suit my needs??

Thanks in advance

an mbrp is a good option . it can be reversed or mounted regular. mounted regular, it is only 3db louder than stock. it is a straight through design also.

Your best bet man is to just straight pipe it where your diesel can breath but if u do wanna do that and u wanna keep it quite keep it how it is because anytime u go with a aftermarket muffler its going to bed a little louder

I have the MBRP single 4" cat-back exhaust. It was very quiet until I installed a muffler delete pipe, which gave it a mellow rumble- not too loud.

You will have some mileage gain, but not much. It will look nice and give you lower EGTs.

I think if you go with a cat-back system with a muffler you will get what you are looking for. It will make the exhaust more free flowing, lower EGT's, but will not be much louder than stock.

Where yours is an 02 I wouldnt go cat back, Id go turbo back. TTS has a system that even gives you a more free flowing down pipe from the turbo, and its only 1 db louder than stock. MBRP systems are nice too though.