My question is how to guarantee my stock wheels can handle the higher pressure? There is nothing stamped on the back of the wheel,
On some yes, but not all with words to the effect "not to exceed XXXX"
And some (like mine) had a manufactures name and model stamped on the back side of rim. From that I was able to look it up on their web site.
Others I've been told (never seen one) that is stamp on the inside of rim and a person would not be able to see it with a tire mounted.
Why do they make it so hard, and not a uniform place on all wheels, who knows. When I was looking for 16 inch rims I found several tire places near me that sell rims with that have nothing on them.