Nice write up as usual pics and all. But you keep comparing a 10.5 with a 6.5 BS to a 10" wheel with a 6" b.s. Bottom line it with all stock Fox Suspension on the reae, you have LESS room with stock spring than with coilovers, With stock sprongs (less room for b.s.), the most backspace on a 10" wheel is 6.5" with a 10.5" tire.
Doing the math, comparing the 2 different widths and and 2 different b.s.'s your moving the b.s. 3/4", thats a lot and and the room isnt there!