Just did the OME912 lift, and around 65 mph when lifting off the throttle I get a pretty good vibration accompanied my noise, and yes, once below 60mph, it goes away. But a round 40 - 60, there is a small roughness, although noting like at 65. Its hard to imagine the lift doing this and it being the rear driveshaft angle, as it doesnt look that drastic. I re-lubed the U-joints and the axle itself..........did nothing to the noise and vibration. its definitely a result of the lift cause it wasnt there before.
I can live with it, but if its doing damage to the trans, diff, etc.....it might be a bigger problem!