My 05 Mustang has a 5 speed automatic with the 3.33 gears. I have the C&L, the Diablo and the Zex kit. Down here in the southern hot weather, I was running 13.7's without the Zex (on ET Streets). I added the Zex and had MV Performance tune it on the dyno. The first night out (last weekend), I turned a 12.5 with a 1.7 60 foot. This is just to give you an idea what the Zex kit does. It should get a lot better as the weather cools off.