I have a stock 11 RAM 5500 that is soon due for tires, and I am contemplating running the 8r19.5's.

I would love to drop the highway speed RPM a couple of hundred.

The questions I have are:

1 Do I need to change rims for the different widths?
2 Do I need spacers on the duals?
3. Will the larger diameter clear?
4a Will, I hate the ride quality?
4b If the answer to 4a is yes, would the 245 70 19.5 (same rollout as 8r's) be better?