Had a simular experience with tire balanceing on my wifes 88 mustang. Had paid the big dollar computer balance job and still bad. Was ready to get new rims when a friend said he got tired of the tire problems and bought a on-the car tire balancer like he used in High schools days and the local gas station. He balanced the tire, used 1/2 The weights and now rides nice. He also went online and found a shop in Michigan that shaves the tires for roundness and his problems are totally over.
