It's usually stamped in the bumper somewhere. That said, you can. Just be aware that if your bumper mounting bolts are loose, the bumper could swing up or down and if clearances are tight, dent the body somewhere. You know, it's funny. In 2000 when I toured the Louisville KY truck plant, I noted that the VERY FIRST thing assembled when building a truck, is that the frame is upside down, and the trailer hitch goes on. I looked at our tour guide and said "Gee... we've been doing it wrong. In our world, that's the very LAST thing that goes on the truck."