I got flowmaster kit 17394- Dual outlet side corners. The muffler in the kit is a super 40, just about the loudest thing they make. I loved the outside sound, but I have a full size fiberglass truck cap, and I was getting some major resonance for a 100-200 rpm range down on the low end. The cap turned the whole bed into an echo chamber. If it were just a plain open truck bed or soft tonneau, it would be just fine. Anyway, I ended up getting a 50 series SUV performance muffler with the same 3" inlet and dual 2.5" outlets. The 50 series is about 5-7 inches longer (I can't remember exactly) than the 40 series, but on our kit, there is a big section of straight pipe before the muffler inlet, so I just unclamped the tailpipes, hacked a few more inches off the straight pipe, and put the 50 series in. Now it has the same tone as the 40 did, just reduced volume. Now it is everything I wanted. I have a 126" wheelbase, and flowmaster was the only one making a dual side corner exhaust that would fit it. I didn't want a straight rear exit since I tow frequently.

Pics in my Gallery

 

oh, BTW, I paid like $360 or so for the original kit, plus another 90 for the 50 series muffler. Have plans on selling the slightly used 40 series when I get around to it. You could buy both at the same time, and sell the unopened 40 series and make up a lot of the difference in price. I bought everything from summit; could have gotten it cheaper, but I've had good experiences with summit, so I paid the extra few bucks for piece of mind. The kit is galvalume, not stainless though, hence the price.