Michelin XZL Speed Help!
 

So i am about to begin my new truck build, and wanted to run some Michelin XZL or XL tires....well pretty much any military tire because I can get them new for $400 a piece.
ANYWAYS, I know the Top Speed is rated at around 55-62 MPH. I was wondering if that is based on usual load weight or based on heat.
Being that I will be running them on a Supercab 6.7 with a flat bed....can i run them at 80 MPH max due to the much less truck weight on these tires? I have seen these tires on large trucks on the highways so I figured its fine.