If your dash pic like the below pic, then it is compatible. The lighter sockets will be gone, and the other services become touch screen. If you need the lighter sockets, need to relocate and figure out by yourself because the unit does not have a spot for the lighter sockets. 

08 chevy avalanche:

If your dash air vent is like below, even it is the auto A/C it is not compatible due to the bezel fitment issue.