Without knowing further, check your wheels. If they are capable of 110 psi, then you should be looking to upgrade your E rated tires to a G rated...that means the Goodyear G614. (although there is a Hercules tire of the same specs...Chinese knockoff perhaps but don't know anything about them) If you tow a lot, then this is the way to go...in my opinion. The general consensus among Carriage owners is that the e rated tire was insufficient and underrated for the application.
Others may say to change wheels to go with a lowboy type of h rated tire...seems like overkill to me.
Much of the information in other posts is not going to help in your application...Carriage is a heavy fifth wheel. The G614 is a high quality G rated ST tire with a 75 mph speed rating and about the only tire that will fit (in a G rated tire). You probably won't find a LT tire to carry the load of a G and still fit.
Visit the Carriage/Lifestyle owners forum for more info....lots of Carriage specific tire information...although you have the gist of it here.