B Body 8.75 in a an body

No Dart body style here, but I have a 67-68 B-body 8 3/4 in a Demon. My suggestion would be to install 3/4" offset hangers, you need to move spring mounts any way so why not. I'm using 5.25" back space on 8" wheel with offset hangers, tires are 275/50-15s.