Toyota Repair: engine vibration, toyota 4x4 pickup, engine vibration

Question
I have a 1989 toyota 4x4 pickup extra cab.4 cylinder,5 speed standard.270,000km.It has a very noticable vibration when you have the rpm's at 2300rpm's.The truck vibrates even sitting in neutral.The exaust appears to be tight.I have had many high mileage trucks with this same issue and have never solved the problem.Are they known for motor mount or front pulley problems?Please help!!

Answer
Motor mount problems normally are worse at idle conditions but it's still possible that it is the cause of the higher rpm vibration, look at the side motor mounts very carefully and check to see if any of the metal parts of the motor mounts touch the mounting pads on the crossmember and reposition them as necessary, if the mounts are ok there may be an engine imbalance for some reason, although this is rare.