Jeep transfer case id??

[JesterFab]

A friend of mine has this jeep, mid to late 70's and we are pretty sure it has the T18 tranny, but we are looking for a transfer case rear seal for the yoke. Schucks, Napa, and Randys didnt have anything that came close. The numbers he gave me off the transfer case are Dana 4 e23-2 and there was another set of numbers 018-15-24 5
any help would be appreciated, or even if you know a site to look these numbers up. thanks

 

[pokey]

should be a 20. the transfer case pic. is a 20 if its an 18 the output would be where the square plate is. www.advancedadapters.com or www.novack.com might have some more info on the #s

 

[JesterFab]

Thanks a lot pokey. it should have been c18-15-24 but i figured it out on the novack site. its a dana 20