I'm pretty sure that even if we set it to three letters that we would be limited on the server side by Fulltext's own set limit. Short of modifying that, I suggest using a search engine's advanced parameter settings to search the site for words shorter than four letters.
Example using bing.com:
Type in:
"site:www.lucasforums.com gob"
Without the quotes, mind you.
That should return all instances of your name being used in chronological order.
FYI, for google you would type in:
"site:lucasforums.com intext:gob". I prefer this one.