I have a 2.7 and I use a MBRP single exit 4' diameter tip installer series cat back exhaust. It was $400 because it was made of aluminzed steel and it's quieter than the pro series. I would recommend this exhaust, it sounds amazing with deep solid tone while being aggressive. After installing it, I noticed a little increase in hp and throttle response AND turbo spool time. Very easy install, you will have to mess with the front pipe, you'll either have to cut it or use the extension pipe provided depending on what size cab and bed you have. I also have a SPD aluminized high flow catted downpipe and it goes great with this exhaust.