Sorry about the late reply. It's definitely something you can do with the bumper in place. I tried to take some pics from behind the bumper to show where I mounted the brackets.
Went riding some trails last night with some friends. It was a good opportunity to test all my lights. Took just a few pictures.
Lights off:
HID headlights on:
HID headlights plus Rigid LED spot:
And all of the above with IPF combo:
Buddy's truck with more LED lights than I can count lol.
Chilling (4 degrees Celcius) at the camp fire.
Poser shot