Last years I converted my 7.2 to a full RS drivetrain with the 4.0 LWFW clutch and the 3.89 R&P / 6th. To round it out, I just swapped out the OEM 997GT3 stainless center for a RS 991GT3 Titanium OEM canter. I also recently installed the Soul valved side muffler deletes. Headers are stock since this is strictly a street car. The 991GT3 Titanium center is basically new and not even broken in as it's still a full golden color and hasn't begun to blue in yet. Compared to the Stainless version, I would say it's a tiny bit more higher pitched, maybe slightly more refined. It's really splitting hairs though. The weight difference between the Ti and SS and right at 8 lbs. which is a nice bonus. Not really sure what the difference is between the 997 Ti and 991 Ti center but I've read that perhaps the muffler is reinforced a bit from the inside to alleviate the cracking issues that plagued the 1sg gen 997 Ti mufflers. I used the OEM 991GT3 tips which are slightly larger at 85mm than the 997GT3 tips at 80mm. The larger tips really look MUCH MUCH better than the skinnier 997 tips. The downside of the 991 Tips is that they are 3/4" longer and stick out past the bumper a bit too much making them look slightly out of place in my opinion. I ended up modifying the 991 tips by shortening them by the applicable 3/4" to get them to fit like OE. The pics below are of the shortened 991 tips.

Overall, I really like this set up with the Soul Valved SMB. I purchased the SMB without the "SOUL" logo to keep the look OEM to the untrained eye. Nothing like advertising to the emission guy that you have aftermarket exhaust parts. The car with this set up has zero drone in any RPM but really opens up and has a nice refined exotic scream once past 3500. The valved ON/OFF transition is very smooth. Overall pretty happy with the mod though it could be just slightly louder perhaps. I also have the SOUL center muffler bypass (again stealth without logo) but have not tried it yet as I'm not sure I want the car any louder for street use. Perhaps at some point I'll give the CMB a shot...

 

The tips look perfect!

 

Yeah, didn't realize how undersize the OEM tips were until putting the larger ones on. This is how they should have been done in the first place.

 

Absolute Perfection!

 

Looks fantastic. How did you end up cutting the tips to shorten them?

 

The OEM tips are composed of an inner tube which is welded to the base and an outer tube (with the rolled tip) that slides over the inner portion. The outer tubes are tack welded (3 spots each) to the inner tubes about 1.5" from the base plate. I simply took an angle grinder to the 6 spot welds and buzzed them off in turn detaching the outer tubes. Once they slid off, I simply cut 3/4" of material off the end of both of the inner tubes with a cut off wheel and then sanded the tips nice and smooth with a belt sander. I slid the outer tubes back over the inners and had them tack welded back in place to the inners. The outers do not need to be modded as the simply slide down further closer to the base. It wasn't particularly difficult, a couple of hours of work. The tips are polished from the factory so I masked them off to make sure they didn't get scratched up in the process. I then sprayed the base with some high temp black paint to give it that new look. Interestingly, the 991 tips are slanted at a greater angle than the 997 tips and they actually match the angle of the 997 bumper cut out even better, more parallel.

OEM 997 80mm on left modded OEM 991 85mm on right

 

100mm is the the way to go