Trailer Tires

Thanks rod, the last tires I purchased were ST 215/75/15 10 ply made in china by the Green Ball corp.At the time 3 years ago I was told they were the best on the market with a low failure rate. I will check to see if Hercules can be found out here.I still think I will try the 16'' wheel to see if they fit ok..
Loco, Yes I have the info at the shop on how to read the tire dates. I just bought 2 car tires from Discount tire and although new had a date of 2011 and the other 2013. The tire store manager didn't even know they had dates on them. I took them anyway as they were the only 2 in the area.