Again it depends on what rear you have. 8-3/4 with sbc axels, 8-3/4 with bbc. They will be an inch different each side.
The pics are both my wheels (weld 2.0 & Bogarts with 9.0 slicks) came off a Duster E/Stocker with stock housing width, 15/10 and both show 4-1/2 back spacing. The drawing shows the measurements of layout of a Duster. Plus the opting of the front of wheel well to 31" fit the 30" tall slicks Hope this helps