No need for higher grade washers in this application
The force needed to deform is way higher than the hitch head is capable, but if there us any movement, there is a wear potential. There should be no movement and if so, something is wrong
Yes you can calculate. Need the front suspension spring rate vs distance curve, but just weighing it easier
IIRC, a 2001 is the transition year and don't remember if yours has the weak design reciever...that has a "U" bracket that attempts to transfer forces to the bottom of the bumper
That very poor design will NOT easily transfer much more to the front axle
If so, best to replace it. A better and higher rated reciever would be about $200 bucks, plus labor
Search on this site using = POS reciever, or GMT800 reciever