so i did my sas and the front came out to about 8 inches of lift. Now i am swapping in a 9 inch into the rear and i am trying to figure out what to do for lift. i have some 4 inch blocks, 2 inch blocks and stock rear springs all from a 1979 f150. I was thinking about using the 4 inch blocks but then it would be sagging like 3 inches in the back. I also can get some 9 inch lift springs from my friend from another '79 f150. does anyone know if these springs will bolt up to my '87 bronco's spring hangers?