My hitch receiver has no label or stamping. I have a 2007 Crew Max, SR5 with the towing package. I need to knew the hitch capacity of the specific hitch that is on my truck. I want hard facts, not conjecture. I've read all the posts about class IV and class V ratings (including statements that the hitch on Tundras is somewhere between a class IV and class V). I know all about the (limited) carrying capacity, and how the tongue weight factors into the total weight. I just want the ratings for the hitch itself. How does one go about looking this up, if it isn't noted on the receiver?