Francisco,
There are a number of different versions for North Wilkesboro, so you may get more help if you are more specific... but I will try as best I can.
If you are talking about North Wilkesboro 2004, then Volker has posted a cup setup (see link attached) and you have a ready made GNS setup by just adjusting the gears. Note that he has made some comments about how to improve which may also help.
Question for Volker
The other version I have is the North Wilkes 2006 version, and if I remember correctly, I tried Volker's setup on the 2006 version and it was way loose on exit (might be mistaken as I tried this ages ago).
There are a couple of other versions as well (a WR, 2 1970 versions and the original Noonan conversion) - but I can't comment on them as I don't have them.
Hope this helps!
Cheers
Brad