Well here's what happened..
First I put the brackets on the bumper kinda sloppy loose, then thought i'd be able to do what CO563600 suggested.. but the problem I had was that the brackets kept wanting to point in twards each other.. I was having a hell of a time.. soon as i'd get one side lined up the other side would pop off or contort to some strange position that made putting the bolt in just about impossable.
So after jacking with it for some time, I did it this way:
First, I bolted the drivers side bracket snug to the bumper, and removed the passenger side bracket from the bumper all together.
Second, I bolted the drivers side bracket (that was connected to the bumper) to the frame, and left it finger tight.
Third, I bolted the passenger side bracket to the frame.. so now I got the drivers side bracket bolted to the frame and snug to the drivers side of the bumper, and the passenger side bracket snug on the frame.
Fourth, I strong armed the passenger side of the bumper up on to the bracket and put the bolts thru.. then I snuged all the bolts up tight all the way around.
Mad Maxx bumper is history, and the stock bumper is on solid as a rock, and sharp as a tack. (thats Fumblin46 speak for quasi-straight, and good enough for goverment work)
When it was all done, and the tools picked up out of the yard, I did a couple victory laps around the yard.. of course that was about 20 minutes ago and its pitch black outside.. but the dogs didn't mind.
Anytime is a good time to take a drive in a stovebolt.