I went from 14 to 16 on my steer tires when i changed from the 8r19.5 to the metric 245/70/19.5. But it was mostly because the tire model i wanted happened to be 16 ply and a higher weight rating.
I think the bigger question is if a 16 ply tire is stronger than a 14 ply tire at equal tire pressure, and that specific pressure being well below both of their pressure limits. This sort of discussion can go on forever.
I digress. Purchase whatever tire has the correct payload. Make sure to weigh your rig if you never have. Going by GVW is good when selecting a tire, but odds are you wont need the max tire pressure.