actually, the very document linked by @marce1000 says that module IS supported:
So does this document:
Cisco 4000 Series Integrated Services Router T1/E1 Voice and WAN Network Interface Modules Data Sheet
I checked the document again, it is kind of confusing. They should have made top column listing the router models stay when you scroll down. Either way, the top column lists 7 router models, the 4431 and the 4221 do not support the module.
NIM-8CE1T1-PRI Yes Yes Yes Yes Yes
If you count from left to right, the 4321 is number 6, that has a "Yes". If you add a "No" instead of the blank space, the entire thing would look like this:
NIM-8CE1T1-PRI Yes Yes No Yes Yes Yes No
Not sure why they not simply put 'No' in there instead of the blank space,