full width explorer rear end?

The wheel wells look kind of vacant with the tires tucked way under there. We are going for sort of an autocross style. Would like to run four identical wheels if possible. Currently has 14" rallys but planning on 17" charger steel wheels. I can get posi, disc brake explorer rear ends all day for about $150. Not much look finding 5 lug mustang gt rear ends at a good price. I would rather go ahead and widen the rear track so the car looks balanced.