Alright, this is something i have never read about happening so here goes. I was at a light today, and i went to go and it felt like my rear tires slipped on the paint line, but there wasnt one there. I am hoping that its not something to do with the gears or anything. My truck is a 03 1500HD 4x4, 3" blocks an cranked keys. Now before anybody says its the blocks, i had this happen before i put them on the truck. Any ideas on what may be the cause? THanks in advance.