Load carrying LT tires work best at carrying those heavy loads when the wheel width is close to the tires tread width.
Oh sure we can play around with narrow wheels using a (example) LT265/70-17 tire with a 8.5"+ wide tread on a 6.5" wide wheel. Owning mostly GM trucks and with the 6.5" OEM wheels since the late '50s I've done it more than once with not so good results.
Doing so can result in the center of the tread ballooned. This can create tire wearing the centers/tracking issues and not the best traction on wet pavement.
Don't cheap out. Get the wheel that better matches the tires needs for load carrying capacities and performance.
