I just did a search on OldTruckStuff.com for UBB, in the hopes to find a UBB board, and I did.
Inliners International uses UBB, (search for Inliners UBB to see a pile o' results) and their path is
http://www.inliners.org/cgi-bin/ultimatebb.cgi?ubb=get_topic They're using UBB Classic 6.7.0.. what I would guess is a little older than Stovebolts 6.7.2 so maybe that has something to do with it.
At any rate, it's up to Peg and John to decide if they even want the board to be crawlable, and if they do.. I don't know how to do it, and apparently neither does Google.