CNH online catalog question

Hello,

I'm using CNH on-line catalog

http://ift.tt/1kp7OWV

and I'm searching for a clutch assembly for a New Holland TD5050, S/N: Z8JN10627 tractor.



In the catalog I find two clutch assembly:

5092802 - CLUTCH & DISC - C6313

and

84177331 - CLUTCH & DISC - D6313



Which one is the correct one?

Where can I find what C6313 and D6313 mean?