I have a weld neck flange I'm inserting into a multi-body part.  After using mates to position everything, I need to rotate the flange to its proper 2-hole position (2 bolt holes straddling the 12 o'clock position instead of 1 hole at the 12 o'clock position).  But, I can't figure out a way to do it.  I can't see any reference geometry in the original part to use to constrain the flange.  Any ideas?