I am replacing my 99 2500 silverado 9.5" rear with one from a 2004 sierra 9.5" rear that is listed as a swap but it has drum brakes. I would like to swap the original 99 disc brakes onto the 2004 rear (replacing the drums). I've seen many discussions about the pluses and minuses of each and have had great experience with he disc brakes and want to keep them and not have to reset apportion valves ABS etc.. Has anyone had experience with this swap and could you give any direction or help. Thanks.