Vibration problem Need help.

I have now removed prop and took car out for a drive. Vibration worse than ever so had to put prop back on. Did notice about 10mm of backlash in rear diff. I have changed both front driveshafts, front prop. all bushes and changed gearbox oils. What to do next ?

Vibration on acceleration normally means the front driveshaft inner CV joints are shot. Replace them with genuine GKN driveshafts only, as cheap aftermarket shafts vibrate anyway. Other causes are failed lower engine tie bar bush.