Hey Gene. I've seen numerous videos of all the different axle back exhausts and was looking most seriously at the SLP Loud Mouth or the Borla S Type. I have a 2012 2SS with the L99 engine and plan to turn off AFM permanently right after installing the axle back system. Do you only deal with the GMPP systems or others as well? I was told that the GM Perofrmance Upgrade exhaust 92206992 does not fit the L99 vehicles, only those with the LS3. Any help would be appreciated.