I have a Gibson stainless on my '93 Club Wagon. It is a 3" single outlet. Even with all the space under there, it was hard to fit over the axle. It is loud and causes resonance at freeway speeds. It is tolerable, but the new Expy is a quiet delight that I would never want to make louder.
Drone! Make sure you ask around when you decide on a setup. Droning will annoy you especially if you drive any distance. They make mild setups that limit this. Me personally would just like a hair more throat over stock and a nice quality chrome tip.
i wouldnt go with gibson. I purchased the side swept for my 05 explorer, granted it was a V6, but it was so loud. It wasnt too bad when cruising, but anytime you hit the accelerator it was ridiculously loud. My wife was pissed...and refused to drive it anywhere, it made getting an 07 expedition alot easier.
Zommies had something for the Titan that was quite nice. I have no idea if they have an application for the 07-08 Expys. Bosani(sp) has a rep of some quality work and numbers but I have never experienced one in person.
So I got the Magnaflow exhaust in the other day. Quality looks good, but for $780 retail, it should have had flanges instead of $2 U-Bolts to connect it together. The exhaust tip is large and looks really nice.
Anyone thinking of doing this install themselves.....FORGET ABOUT IT. First, you cant remove the stock exhaust without cutting it because of the funky bend over the rear suspension components. Second, you cant get the new piece with the funky bend over the suspension components. I tried for almost 3 hours and ended up taking it to Meineke. Even Meineke said they had a hard time with the bent piece, they had to drop the sway bar and shock to get enough clearance. I also had them weld it up instead of using the U-Bolts.
Once installed, it looks really nice and sounds great. It's very quiet at idle and low speeds, but has a nice deep sound when you get on it. It's not too loud however where your wife might not like it.
Overall, I very pleased with it. I just wish I hadn't wasted 3 hours trying to do it myself and just paid a pro to do it from the beginning.