I installed the bumper brackets first, left the bolts loose, and just started the nuts.
This will give you a little side to side play so you can line up the bracket with the bumper and apron. I may have temporally used some longer bolts through the frame
Went to Lowes and bought a few long carriage bolts for the bumper to start off with.
Then drew it in with the nuts. Once everything was assembled changed the carriage bolts (one for one) with the bumper button head bolts.
I had to use a strap ratchet on the bumper brackets to line everything up.
I used repo brackets and the fit was poor.
What I did was leave everything loose, started all my fasteners. Then started to tighten