The tires on the Niagara are 205/75R14 50 PSI GY Marathon LRC(capacity 1760lb). I would like to replace them with the new GY Endurance tires. These are LRD(capacity 2040lb) tires with a speed rating of 87mph. They are however need 65PSI while the Marathons are 50PSI tires. I can't seem to find a max rating on the aluminum Niagara wheels. Googling seems to suggest there should a stamped rating inside a circle on the wheel, but I don't see anything like that. Another 15PSI doesn't seem like it should be a problem. Does anyone know anything about the Niagara wheels?