Just thought I would share what I've done to get a wider rear tire on my 78. I want the widest tire I can get without doing mini-tubs. And since I'm doing a full restoration I didn't want to just hammer/flatten the seat belt bump. When searching for what others have done I found that they were relocating the seat belt housing and trimming the plastic side panel. After spending a great deal of time measuring I've determined that I can make this modification and leave the seat belt housing in the place. This eliminates cutting out the threaded fitting and no mod needed to the side panel. I now have 7" backspace clearance at that spot and now the limiting factor is the DS shock at 6 5/8". Leaf spring is 6 7/8". Photos of modification included.