[@ipstenu Moderator 15 years, 7 months ago]

Mad idea.

Convert it to phpBB2 (NOT 3!) – http://forum.yetanotherforum.net/default.aspx?g=posts&t=782

Convert phpBB to bbPress – http://www.iteisa.com/phpbb2bbpress/

See also: https://bbpress.org/forums/topic/import-smf-to-bbpress

If you read the SMF to bbPress thread you’ll see what machinations were needed. Good luck!