I spoke to the preson at our Goshen Rally that talked about the tires that Heartland was now using. He said if the rims had 7 spokes with no split in the rim it was a class G rim. I looked at my spare, which is a steel rim, and on the insice of the rim it says the max gross weight is 3750. I believe all the rims should be the same grade as the spare.
So take a look at your spare on the back side of the rim and see if it gives the weight limit. You don't have to remove a rim from the ground to check the rating of your rims.
BC