I have an 00 Dak 4.7L CC 4x4 and am considering putting on a Super 40 Flomaster 2.5" inlet/dual 2.25" outlet. Is that such a wise idea to run the smaller diameter pipes out the rear? Logically, I'm thinking that will keep the backpressure the same or even lessen it a bit more rather than do 2.5" dual exits. Has anyone done this before and can tell me how their Dakota ran? I'm trying to not sacrifice power (trying to gain some actually). Any suggestions are appreciated.

Was originally just going to replace the stock muffler with a single in/single out flowmaster super 40, but after looking at that odd-ball stock muffler, I decided it would probably be easier just to replace the whole thing.