Exhaust size for muffler swap - Help Needed

[PATrailBoss19]

Hey guys, new to the forum hoping you can help me out. I have a 2019 TrailBoss LT with the 5.3. I wanted to just do a muffler swap and keep the stock exhaust pipes. I like how they exit in the bumper, and well, price is a cheaper of course. I keep finding mixed information on exhaust pipe size. 2.75" vs 3". Several have shown it is a 2.75" pipe, but i need to order a 3" muffler, so its not really making sense. Since it was my chance for Xmas, I told my wife what i wanted and she actually ordered it!!! I got a Borla XR-1 3" muffler (PN#: 40085), complete with a 3" SS extension pipe and 3" clamps. But as I am not sure this is the right size. Can you help out before I go cutting things before I am ready.