If it was me I would look at seeing about 16" rims and LT tires, if you have the clearance to run a taller tire. Every ST tires I've seen advises max speed at 65, LTs are rated at 75 mph.
Option #2 if you can't go to 16" rims is to look at upgrading capacity in a 15" tire/rim, ie if you have load range D, go up to E. Rims that come with D rated tires from mfr are usually rated at 65 psi, you need 80 psi to get max capacity from an E tire.
If options 1 and 2 are no good, then I would get 4 new Goodyears or Maxxis if you an find them, and save those Chinese Hi Balls you bought as spares. Be sure to look at the DOT code and try to get the freshest tires you can, because regardless if you spend $50 or $150 per tire, they need to get gone in 5 years.