I was reading the Slee Bumper installation instructions last night and it seems like there are only the 2 bolts by the tow hitch that bolt into the rear crossmember. So, with the exception of those 2 bolts, could you theoretically install a sleed bumper onto a 100 that's had it's rear crossmember cut out? For example switching from a 4x4Labs or BIOR HC style bumper to a slee?