I just did a cab off engine replacement on a 2003 6.0L. Installed a 6007. Crank the motor and it runs fine, no problems noticed while I finish installing interior. When I get into the truck to test drive it I notice a vibration that feels like a misfire. No misfires on powerbalance and vibration is still present with accessory drive belt removed, engine oil level is not too high( hotline said that would cause vibration), unhooked downpipe from truck to see if it would make a difference. Nothing. Any help would be greatly appreciated before I go back to work tomorrow and pull the transmission to check flywheel. Grasping at straws here. /forums/images/%%GRAEMLIN_URL%%/banghead.gif