73 Bumper Fitment

Can someone please tell me what the heck I'm missing here? Trying to mount the bumper to my 73, with 73 brackets, and a 73 bumper, it is sticking out about 4" too far, and refuses to get tight against the body. I attached a couple of pictures to show where it is sitting, and they are terrible, because they were taken one handed trying to hold the bumper up with the other. One shows the top, the other the side.

I compared the brackets to the ones on my Dad's 73 Dart Sport and they are in the right spot, same shape, size, etc, but his bumper fits right and mine doesn't.

Any help is appreciated on something I haven't thought of yet.