Just to clarify a few things. It is a CA conversion with a BW78 (Not a stock 1200). I opted for a 2 degree difference when setting my pinion angle. Possibly the slight downward angle of the CA box could be an issue. Maybe 2 degrees is not enough

The diff also makes a slight noise when you back off the accelerator. It is quiet on acceleration and when the vehicle is de-accelerating. Going to ask the diff builder about this as it is fully re-built with new crown and pinion.

Car also mahes a hmmm noise at 100kph. It is not a constant noise. It is more Hmmm .... Hmmm .... Hmmm and the frequency increases as the speed goes up to 110 etc. The yuy from the tail shaft shop said this could be an indicator that the pinion is slightly out when the car is under load.

Spoke to the tailshaft guy who built the tailshaft which has new uni's and he said it is not un common for uni's to get too hot to touch, but he offered to come for a drive in the car next time I am in Perth and give his opinion.