another tow vehicle replacement tire question

So this tire dealer in Fl. has a sale going on buy 2 get 2 free only catch is a wheel alignment you pay for, so I called and told him I have BF Goodrich Rugged Trail T/A LT265/70R17 on my Dodge Mega cab. I told him I pull a 16 K 5th wheel and I need a good tire. He told me I should go with a Sumitomo All Terrain which is a 60K mile tire and 10 Ply. I told him I didn't want any China tires, after I asked him where the tires came from he told me Japan. I'm just curious about these tires and what everyone else has as a replacement. My BF Goodrich that I now have has seemed to serve me well and has about 45 K on them and could go alittle longer, I am diligent on rotateing every 7K so I'm sure that has helped me with longevity. Should I stay with BF rugged trails that has served me well ?? The guy telling me about having a 10 ply tires has got me thinking cause I don't know what the plys are on the BF's. Whats everyones thoughts ?? Thanks

the tire ply rating is on the side wall of each tire. it may be listed as a alpha figure, such as E would be the ten ply I think, G is 12 ply and so on. anything less than a 10 ply on most rigs is not a good idea. of course, this is my little bit of info , I am sure you will hear more. God Bless ya, Al & Dee Weaver

I would go with same size and rate of tire that is on the vehicle plate. A little bigger with less ratio be ok. The dealers want to sell you the tires they make the most profit on. I usually never listen to them I get what I want, or go somewhere else.