Since I've had my 82 G20 I've replaced the engine, trans, u joints, motor and trans mounts, front wheel bearings,tires, wheels, shocks, springs etc. Still when I'm cruising down the road I have a vibration whether i'm on the accelerator or not (worse when I'm on it) I've had the wheels balanced twice, alignment from a reputable shop. My next move I guess is to rebuild the rear end? Has anyone had this issue? Any ideas of anything I might be missing? Thanks in advance! CHEERS!