1964 VALIANT disc conversion from 1975 Dodge dart

ok I see the difference in the centering of the bolt inside the bushing, is it a different length?
The problem I'm having is in the first pic, I have the original upper stacked on the dart upper. the dart seems to be an inch forward of the original.

I'm not seeing where the new bushing is going to move the upper backward when the brackets on the frame don't seem to have any room to move backwards.

OK after playing with it a few more minutes....
The hole in the frame is a slot that allows for a lot of shift front to back, hence the concentric bolt that can hold it in place. I think I got this now.
Thanks for all the great information here!