I dug into this a month or two ago. Heads, indeed, need to be below a certain number if you want to be able to select them during character creation. If my source (a guide by
hannibal lecture from 2004) is correct, the number needs to be below 49, this should be the maximum number of heads allowed for any race/gender combination.
Another possibility is the following: while you can change the name of the .mdl file of the head, there are a number of lines referencing the model name in the file itself as well. Open up the .mdl with notepad (or equivalent) and see if the model name and nodedummy are correctly changed to the new number as well.
These are my guesses, maybe someone that is more proficient on custom head creation than me can shed a brighter light on this matter.
Edit:
While you can use the override folder to add heads, they also work when added by a .hak. Your preferredmethod would be determined by your download in this case.
Modifié par Valthrendir, 10 décembre 2013 - 08:16 .