Update:
It was great and also had its moments. We left Grand Island on Route 281 and then picked up Route 2. That was a wonderful and very easy drive. When we turned on to Route 83, there were a few grades but they will all very short. North of Valentine, the road gets worse and then a lot worse. The last 30 miles into Merdo were really bumpy and had a least 1 - 7% grade (dropped from 65mph to 45mph in less than 1/2 mile) We caught part of the weather that went through Valentine and that didn't help at all. It wouldn't have raised my bloodpressure even a couple of points without the rain and wet roads with a truck climbing up my tailpipe on the down hills.
Thanks again for all of the feedback. We'll probably take the same route down unless someone thinks Route 183 is better. I wish all of the roads that we get to drive were as good as the part from Route 2 to Valentine. It was terrific!
Charlie