The "dished" steering wheel was one of the first attempts at protecting drivers in case of a crash. It allowed a couple of inches of deflection of the steering wheel before a driver's chest encountered the steering shaft. If you change over to a slightly smaller diameter, flatter shaped custom wheel, you'll gain a few inches of room for "fallen chest muscles"- - - - -just remember to wear a seat belt, and/or adapt a seat belt/shoulder harness setup to the truck.
Jerry