I have seen a 2012 GT with 3.73's run almost 12 flat with a tune, CAI, headers and X-pipe (good driver too!). This was on street tires. I would think if you added these same modifications to the Boss, you would see the mid to high 11's
Stock BOSS have run as fast as 12.33@115 and 11.7@117 with just tires. Decent amount faster than a GT but it could be made up for with a few mods like mentioned.
I ran my Boss with nothing more than drag radial and it was my first Manual transmission I ever raced, This is the first time slip and the very first time I raced it, I figured it would have been a 12.4 Look at the 1/4 mile 70mph,LOL I coulndt find 4th and coasted down the track and still did 13.7. LOL
Here were the mods on the 5.0 - SCT Tuned - MMR Cold Air Intake - FRPP Boss 302 Intake Manifold - FRPP 4.10 Gears - Flowmaster Hushpower Mufflers - Steeda Ultralites - Steeda Tri-Ax Short Shifter - Steeda Upper 3rd Link (Upper Control Arm) - BMR Lower Control Arms - M/T ET Streets 275 40 17 @ 11 PSI