ive had the intermdante shaft replaced on my 06 2500hd 2 times and the clunk in the upper portion is still there it feels like its in the steering wheel itsself! but i also can apply heavy pressure on the steering wheel and it has slack in it like an inch i can push it hard and it will slide forward and then pop back when i let off. i purchased a new lower steering bearing

its the new green part that replaces the white factory part could this be it?

 

well, welcome to chevy. mine has same clunck coming from the upper steering wheel mount. shake it and it plain cluncks loose. so do have many others. made so. next time you replace intermediate shaft, buy one from napa, that's a rugged one! completely different design.
you sure you do not have telescoping coulmn? also, they make them collapsable in case of accident.