Narrowing an 8 1/4" rear end, how is it done?

The Pull-A-Part in Augusta, SC always seemed to have a good variety of old cars, but I haven't been there in a few years.
I think things have changed at Pull-A-Part. I searched for any Plymouth model between '65 and '76 in Georgia, Tennessee, Alabama, and South Carolina, and came up with 2 pre-1990 vehicles. Technically, the one you mentioned is in Augusta, GA. It backs up to the west side of the river. The east side of the river is SC. But I knew what you meant :)