Do you have a vin or picture of an Allison behind a 6.0. 07 classic body style will get you a 4l80e or 4l85e behind a 6.0. 07 gmt 900, and 08 and up get you a 6l80e or 6l90e. The 07 6l's had a few small issues and the way they shift takes some getting used too... Login to read more.