Just bought one of these bad boys from kragen the other day. Skf 471413. (napa 12363)
to my suprise, the front input seal is not included in the royal seal kit for the Dana t18/19 kit. Seems that this seal is only made by skf and is not reproduced by any mfr.
Be aware, this seal is not fully encased like the seal you removed, so the back (the spring side) is open. Unfortunately, you will need to drive this bad boy into the bearing retainer housing with the spring facing you. This can be a pain in the arse, but if you find a socket or something that is the proper width, it is not big deal ( the inner fork tube of a 1998 ktm 380 works excellent...)
if you drive this seal in the wrong way, the lip will not ride on the sealing surface in the correct spot to stop your flood of 50 wt. Once you have the part in hand, it makes sense.