This is what I'd like to do. I want to keep the 73-74 bumper guards but do away with the filler panels and move the bumpers in next to the body. This would still keep the look of the 73-74 but not have the bumpers sticking out sooo much.

How would that be done if the 73-74 bumpers won't bolt to the 70-72 brackets? And if you could get that to work, will you be able to see the holes in the fenders were the rubber filler pieces clip on? I have an extra set of 73-74 front bumper brackets if there is a way to modify them.

I have several pics of 72 Challengers from the Mopar Nats and they do have slots in the bumpers for the jack, just like what was stated above.