I plan to redo my stock exhaust system and I'm going to do BBK full length headers, a BBK catted shorty x pipe, and I've really been liking the sound of the Borla s-type axle back mufflers. The only problem is the tubing on the BBK tubes are 3 in which is ideal, but the Borla's only have 2.75" tubing. Will this affect any performance gains? Should I look for 3" mufflers to match instead? I've also heard that 2.75" for mufflers should be fine in a dual pipe setup? Any help is appreciated!

 

I have found that no one company produces a full exhaust system from the engine to the exaust tips that meets my expecations.
I have purchased Hooker ceramic coated headers and Dynomax X flow muffler (mounted just forward of the axle) and will run a 3" dual exaust to correspond with the factory location. Similar to HawksThirdGen offroad racing Y-Pipe. I'm not installing a cat. It's about simplicity and I like that the Dynomax muffler has a built in X-pipe.
Good luck!