After much delay from Amazon, the ProRac finally arrived and spent this morning installing it.
There is still some good length left on the poles after using the tallest hole, so I may just drill a new sets of holes. But after a dry run with it set to the tallest hole, I think it should be just fine.
Here are two pictures of my dry run and my bike:
2013 Forest River Rockwood Highwall 296
1991 Chevrolet Suburban V2500