I just did a Duster. With stock tubs and wheel lips you can fit M/T 275/60x15 Drag radials on an 8” rim width. It required the front hangers to be spaced rearward 1/2”. Clearance is tight but it won’t rub anywhere. The width of the axle will depend on wheel off set. Get the tires and wheels you are going to use. Mock them up in the wheel wells. Measure the distance in between. Then figure drum or rotor thickness. Get the axle offset from what ever axle manufacturer you are going to use. You now have all the necessary dimensions you’ll need for housing width. I usually remove an additional 1/4” per side just in case. You can always add spacers. But you can’t get it any narrower.
Doug