Sorry for not posting sooner. Truck went back together very well. Valve adjustment procedure was a little confusing at first, but I got it done and it ran great. I am very disappointed in my Mack dealer though. The truck came from a large fleet and had a 65 mph speed limit. I was also second guessing myself about the valve adjustment so I decided to take it in and get them to increase the road speed and adjust the overhead. I also asked the service adviser if the HP could be verified and increased and he said there was nothing they could do. I have taken a few of my other trucks to them in the past and have had no trouble. This time they kept my truck almost 3 weeks to run the overhead and to increase the road speed. They said they were about a week behind, but they should be able to work me in since it was a simple job. After a week I started calling them every day and I got the same response. They kept telling me they were almost done and to call back that afternoon and in the afternoon they would tell me to call back the next morning. I finally told them to put back together whatever they had apart and I would come get it. When I got to the shop to pick it up, they said it was done. They charged me $100 to check the fan clutch (didn't do anything, just verified that it worked), $650 to run the overhead, and another $650 to increase the road speed. I was upset to put it mildly. It was late on Friday afternoon when I picked it up. All the important people were gone from the dealership. I called and left messages with the service manager as well as the branch manager, but haven't heard back yet. Not only do i think the prices are a little high, but they screwed up my engine hours, the ABS and traction control no longer work, and the speedometer is way off. The work was done by Tri State truck center in Jackson, MS. Does anyone know if there is a main customer service number I can call and get some help? Can the hours be set back correct? Sorry for the long post. I appreciate any help.