Thank you for the reply, The brakes should be in good shape I only have 20K on the truck. The U-bolts were new but i'm ordering a new set just for peace of mind. I'm going to swap tires this evening and try it. If that don't make a difference i guess i will take the block out and try it. I think i can get away reusing stock U-bolts for that just to trouble shoot and order new bolts accordingly. I wouldn't think that would change the angle enough to cause the vibration but I could be wrong. Could the transmission cause a vibration like that.