Do you have pictures of where it's cracked? If for some reason the sprag rolled (it's not common but still possible with enough abuse) and the outer sprag race damaged the case, then a bolt in sprag may be an option.
Will this project remain automatic shift? The RH transmission was hydraulically governed through model year 1995. If you were going to something like a 1-4 reverse manual shift valve body, then you can buy all means use the entire 46RE transmission core.
If this project is going to use aftermarket fuel injection with Holley management, you can use the complete RE core, you just need to add kickdown linkage. Holley management will control an RE trans. I worked with the Holley fuel injection engineer to provide input on how the RE transmission worked for 4th gear and overdrive, while they were developing the software to control the Chrysler RE trans.