The 65-67 B-rears are the narrowest of the bunch, and the best fit in an A-body. Go ahead and relocate the perches to A-body width to keep all your existing wheel well space, or go for another 3/4" with a kit from DoctorDiff and others to max out without cutting. An 8" wheel with about 5.75" backspace should be a real nice fit, and you could go wider in a Duster if you measure closely.

Clair