I'm sorry about the question my roomate asked earlier today. The question I wanted him to ask was what is the difference from the torsion bar keys that come on the truck from the factory and the green keys you can buy from the GM dealership, how much more lift can you get with green keys over stock and how is ride quality effected?

After the same answer today, hope somebody replies soon I am getting ready to buy new tires and this will help me to decide.

They are clocked a few degrees more to allow more torsion bar adjustment.

http://dieselplace.com/forum/showthread.php?t=86748 Read this thread I'm sure it will help. The keys are also talked about in many other threads.