No regulation as such how long the grace period is for you to look for a new job. Since you're not going to COS, you may always file H-1 xfer no matter what the gap is. You may receive approval w/o I-94 while you may also have good chance not to have to apply H-1 visa.
http://blog.wenxuecity.com/blogview.php?date=200711&postID=37365