Because Racecar now has the new magnaflow catbacks available for the 2015 GT's!
19100 is the part number for the street: http://www.magnaflow.com/02product/displayapplications.asp?partnumber=19100
19101 is the part number for the competition...
We actually have a product for this that is removable and the main bracket stays on the vehicle and cant be seen.
We have them for S197's and Lightnings...wont take much to adapt is to the new '15s.
with the 6R80 having a 4.17 first gear...either is going to be fine.
3.15*4.17= 13.1355
To compare with the old new edge 4spd auto
4.56*2.84=12.9504
So the 6R80 with 3.15 rear gears has a better first gear ratio than the old 4R70's with a 4.56 rear gear. Phenomenal.