vibration
i have a 1991 Ford Rager ext.cab reg. box. I have a vibration at 43-48mph. No vibration t other speeds. we have put new u-joints and driveshaft center support in it also, all new ball joints rotors, bearings, tires, drums, rims are not bent, front end alingment, no rear end noise, all of this and still the same vibration. Thinking maybe driveshaft out of balance it is very rusty, made mistake of sanding driveshaft. could this be my problem. Also haveing trouble finding new driveshafts at local parts stores (everybody has them for reg. cab).
Can anybody HELP ME!!!!PLEASE!!!!!!