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!!!!!!

I had a Jeep in at work recently with the same problem, chased everything down and it did end up being a bent driveshaft. The vibration was in the same range as yours.

As for getting a new one, depends on what part of the state you're in. I use D&R Driveline in Jenison. Great work and good pricing.