Sorry - those tire types weren't qualified....post deleted!!!
Jaycos website identifies the 2012 Sport Series as being shipped Load Range C
If you dont have a factory sticker....It's important to identify the identify the tire to determine the proper max pressure and stay with that......
Special Trailer Service Tires (ST)
Special Trailer Service tires are often available in multiple load ranges. The appropriate load range is identified immediately following the size's rim diameter in Tire Rack's descriptions.
ST-Metric sized special trailer service tires will be branded with their load range (Load Range D or LRD) on their sidewalls and list their appropriate load range letter in their descriptions as ST205/75R15 LRD.
Load Range Ply Rating Max Load Pressure
B 4 35 psi (240 kPa)
C 6 50 psi (350 kPa)
D 8 65 psi (450 kPa)
E 10 80 psi (550 kPa)
There....that looks better