Is it a driveline vibration?
Ok, do you feel the vibration in your butt or in your hands?
Butt means driveline: engine mounts, tranny mounts, u-joint, bent shaft, bent rim, lost wheel weight (most common culprits)
Hands means its in the front end: bad u-joint, wheel bearing, ball joints, tie rod end, bent wheel, lost wheel weight(common issues)
91 YJ, 350/700R4/231, 8.8/HPD30 with 3.73s, 6" SOA with 38" TSLs. If I ever see the previous owner again, I am going to curb stomp that meth-head brain dead crackpot.