had a similar problem, changed out the steering stabilizer. my truck has 331,000 on it and still had orig. part and was just waisted. It was more of a shimmy on the steering wheel from start off to about 40mph and when I moved left or right it would get worse. Just something to look at. Tire balancing check your front end to see if tie rods are good. Wheel bearings. Jack up truck and start wiggling the wheels for excessive play. Hope that helps

86 toy 33's custom camo paint dura liner black steels 3 inch lift stock motor