Bad vibrations in a 1995 Toyota landcruiser

Experiencing vibrations at speeds of 30, 50, 60 & 70 mph. No vibrations in park or nutral. Replaced tires, ujoints & repacked all 4 sets of wheel bearings along with having rotors turned. Not sure what the next steps are to stop these vibrations. Please help.

Could be a number of things. Your alignment might be out, or you might have a bad tie rod or ball joint just on one side, causing a wear on one tire. As you increase speed, the wear on your tire is causing the vehicle to ride on an uneven surface. OR, your motor mounts might have given out, causing your engine to rattle at higher RPMs. If all else fails, check the bolts on your seat!

Thanks for the reply! No loose front-end parts that I can tell, old tires were worn pretty evenly. I had the motor replaced about 20k miles ago and vibration was occurring before and after that time. The mechanic that did the motor replacement did not notice any issues with the mounts but I will go back and check it out. And yes, the seat bolts are tight.

Could this be coming from innards of the Barfield solid front axle by any chance? Anyone have any experiencing with these?