Decide on tire sizes first. Below is a picture of my 80 SC with standard suspension. Rears are 17x11 et-19 with a 12mm spacer (effectively et-31). I have 275/40 tires on them and it's very flush to the fender.
Fronts are 17x9 et8 with a 245/40 tire. Good fitment without any rubbing.
If I were to do it again I'd stick with my tire sizes and get a 10.5 wide wheel in the back. PM me if you have questions.
