are 4X4 front bumper brackets diff?

I just got a CkorSport bumper and there are 3 mount holes along the top lip on each side. The 2wd brackets I have only have 2.

The only difference are the end caps on the bumpers

i dont know wht the extra holes are for. i used the 2 up top, it had a spot for 1 on the bottom. then i drilled a hole for the other lower one and put a nut and bolt in it.