Understood. At least on a Toy mini Axle. But for a custom width axle that see's speed a deeper back spacer is good for ditching scrub radius and turn radius. If I were doing my Diamond axle again. I would be going with a 68" WMS and 5" back spacing. It also puts less stress on steering components and the trunion bearings. For reference Im 62" with a 3.5". I would be 3" wider with less stress on the same axle. Its all kind of a compromise.