Initial review:
Bottom Line Up Front:
Overall, I would recommend this to a friend! Sounds great, only marginally more audible from inside the vehicle, and noticably peppier around town.
For some background, I honestly didnt want anything louder than stock, and neither did my wife. I bought this because it was like $100 more (with this sale) than buying a new OEM exhaust, so it seemed like a good deal.
However, it sounds very, very good at idle. Outside the vehicle and calmly pulling off, it sounds more like a hefty V8 than I thought possible (reminds me of like an old Suburban pulling off). Not that it is loud, but to call upon everyone's favorite exhaust descriptor, it is surprisingly "throaty." Above about 2500 rpm it starts to sound like a V6 again, though it is also a little mellower at those RPMs.
My wife said the increase in volume is not really noticable from the front seat, but when she later rode in the back with our kid she said it was a bit more noticeable. However, she absolutely hates loud vehicles and didnt actually complain; rather, she just remarked at the new sound.
On the highway, I did several runs at 70mph, using a phone app to measure cabin volume. I saw no overall increase in volume compared to previous measurements, but I did actually find about 0.5dB more volume in O/D (2150rpm) than in 3rd gear (~3k rpm). This seems to match my ear where a combination of the higher engine load and "throatier" tone below about 2200 make the sound just slightly more audible. In either case, even my factory radio was able to jam plenty loud enough to enjoy. Also, in my experience, tones like tire whine are much more disruptive to music and conversation, whereas this is low enough in pitch and smooth enough in tone that it was not a distraction. FWIW, I literally grew up in a recording studio, so Id say I have a pretty well-trained ear in that regard.
As to my install difficulty. My OEM muffler inlet pipe was 2.40" OD, and the Gibson inlet was 2.37" ID. So, it just barely didnt fit, and I ended up just welding it. However, I spoke with Jason and he is going to get with Gibson to make sure nobody else sees this challenge. In any case I have never heard of this issue with these exhausts (and Jason said he has sold like 25 or 30 with no issues), which is why I think mine was a fluke. Like I mentioned before, I am wondering if my exhaust had been replaced at some point and the piping was not exactly the same size. But, I trust Jason is still going to dig into it to make sure!
FINALLY comes the biggest surprise. I honestly didnt expect any increase in power or pep. However, several times today I found myself accidentally doing 5-10 over the speed limit, where previously I almost always did 0-5mph below the speed limit (I really do drive like a grandpa). After paying more attention to it, I realized it actually takes noticably smaller throttle openings for everyday driving. I can't speak to peak power or even WOT performance as I have literally done that once in this rig, but for city driving it does seem peppier. My wife was happier that maybe I'll drive a little faster now...
*edit*
Per JasonB, the OEM exhaust pipe should be 2.25" OD, so I definitely think mine wasnt the original exhaust, then.
