User blog comment:Plexioth- xD/Monster Hunter 3 Ultimate/@comment-82.132.248.57-20121102232447/@comment-4212769-20121103103044

Actually you could upgrade all the armors in MHFU to a G-Rank defense after killing Ukanlos. Means even low rank armors can have G-Rank armor defense.

AFAIK it isn't in MH3U but I can be wrong.