I have an 89, lifted 3" in the front and rear, and when I'm going around 45-55 mph, and turn about 10degrees to the left, and to the left only, I can feel and hear a vibration underneath my feet. Its only left turns too, which is a bit strange to me. No I haven't had an alignment, but I think it would either be the driveshaft or the U-Joints. Any opinions?