I bought a Denali Cluster off Ebay a few years ago. The mileage was 0. But I installed it and ended up putting about 20-25 miles on it, mainly because I wanted to make sure all the guages worked before spending the money to get it programmed. Then I call tons of dealers, some said they can't do it. Some said only if its 0 miles on the cluster, couldn't do it if the cluster had miles on it, and said nope even with only 25 miles they still cannot do it. One dealer said only if I buy the cluster from them (fuck that). I ended up selling the damn cluster for what I paid for it because I found a HD cluster with almost the same miles as mine. I also talked to a guy who I know that worked at Best Chevrolet in Metairie. He said he talked to the guys in the service dept, and they said they can do it with a Tech-2, but they "ARE NOT SUPPOSED TO" do it if the cluster already has miles on it. He was telling me that if I brought my truck in for something else that would require a tech -2, that they could hook me up and reprogram the cluster while they were at it, but it was too risky to have me pull in and they just hook me up. I never got around to doing it though, because I had to have the truck present and I didn't feel like driving all the way down there just for that.