Thanks for the info... I know theres a driveshaft shop close by, maybe i'll just take out the shaft and let them check it out, balance, whatever. As for the rear tires, They're the same size as yours, except I have a bit narrower wheel, but i still think they should be able to use stick on weights near the center. I know the plug wires are right, but I will double check where the 5 and 7 run in relation to each other... one other thing, any chance it could be in the rear end? I know its just an old open rear out of an old ford truck or Grenada or something... factory gears and all... any chance it could be a bent axle or something like that?