I have an early 99 350 4door dually auto. It now has 54,000 on it and it has bad piston slap. The dealer has been telling me it was bad gas and/or sticky valves. It seems it does go away for a short time right after I change the oil. After looking through this website, I now know what the real problem is. I am trying to find the TSB on the valve slap issue. The one where the mfg. was making pistons with variable tolerances. I hear the problem was corrected after April 98. My truck was built prior to that. Can anyone help me find the TSB. I also have the brake problem(chatter). I had the alignment problem and wore through two sets of fronts. I finally took it to a specialist in front ends here in Tucson. He told me there was no way the front end could go straight the way the dealer had it shimmed. It figures. I will battle this to the end. The service manager had the ----- to tell me he doesn't believe I changed the oil. Since it is out of warantee, they are trying to stick me with the repair for a new motor at $ 6,500.00. Not in my lifetime. I would appreciate any info, especially someone who works at a dealership. My email is justgottadraw(No Email Addresses In Posts!)