[LifesGreatestGift]

one way or another there would need to be a custom field in the vbulletin thread editor to allow you to reference the ID of the post in Drupal. Once you can do that, the rest is just simple database calls and auto-template edits with a FIND-REPLACE for the canonical tag.

--------------- Added [DATE]1360039349[/DATE] at [TIME]1360039349[/TIME] ---------------

That's the somewhat simple method. Another method would be a full blown backend where you would enter forum thread id, drupal post id and do all your php on the backend to prevent users from messing stuff up.