[tdangle]

I'm currently fighting this. Stock C20 long bed with 2 piece driveshaft and 4.10 dana 60 gears. working angles after shimming the center carrier and rear end are all less than 2 degrees and still have vibration at about drive shaft speed of 2-3K rpm. Seems to get much better at higher speeds and at low speeds. It's not engine, trans, wheels, tires, brakes all have been changed out.