would 3" be better than going with 2 1/4

 

Not entirely. Stock is 2.5".

Depending if you are going dual exhaust or not.

If going single 3" is definitly better, however if going dual, a 3" inlet to a dual 2.25" outlet is better.

 

I have the Flowmaster 1-in-2-out with duals under the rear bumper. Chrome megaphones. No clearance problem with the spare. It resonated quite loud so I added a straight thru resonator in front of the muffler. That made it sound nice, on the loud side when my foot is into it but nice deep rumble at cruise speeds.

'05 quad, 4.7, auto, Airraid cai.

 

I have a super 40, single in / duel out. The truck had originally two resonators, I had them keep the front one on, and take the rear one off. The truck sounds absolutely beautiful, and unique! :-)

Flowmaster super40
Dual pipes