They used to offer it and stopped offering it when the surply of standaard 318 LA heads dried up. MoPar performance can only surply performance parts, factory enhanced parts, so long as the factory makes/uses them. This is also why other parts are no longer available.
727, 904, 518 and 500 tranys. But they have parts for them since there still being serviced.
The 440 creates are slightly different stroy, but at one time offered many create versions. There down to what now? A create shrot block and one 40 create engine?