What is the Size of the Stock Exhaust piping?

 

After the y-pipe it should be a 3inch. thats what mine is, can imagine it being smaller for a 6.2.

 

What can Black Bear Performance Tunes do for my 2010 Chevy 6.2L? Is it worth it and how hard is it to install.

 

blackbear will open up a whole new world when drivin your truck, but if you plan on doin other mods, just go ahead and get them on before the tune so he can tie everything together rather than go back and retune it