As I said earlier, I did all the carpet oil and C/W adjustments to good effect but also I ran a long 1/2 " drill through the top diff mountings because they are 2-3mm out of line when new. Many new builds hammer the top bolt through which preloads the rubber bushes.....just saying! 50mph whine I think is a resonance in the prop shaft....I`m considering shrink wrapping it!