I've got a vibration under load at highway speeds, thinking my drive shaft could possibly be out of balance. I noticed it has a shinny spot on the drive shaft and my crossmember has an area in which is also shiny above the driveshaft. Just wanted to get some input from anyone else lowered 3/4 and a c notch. (i also do not have the shims under the springs installed for better driveshaft angle)