Excellent idea! I know it may be overkill but based on John's comments, I would extend the top and bottom bolts longer and duplicate it on the other side. In otherwords, add a steel plate on the other side and put bearings on that side also. The top and bottom bolts would just extend through the angle on the other side. Unless you could drill the holes just right, you could make then adjustable with the size of the holes so it can be tightened to the steel plates. If you didn't want to add another bearing set on the opposite side, then just use longer bolts on the top and bottom with spacers and put a metal plate on the outside with those bolts connected. This will reinforce it with the weight of the gantry.
Just my two cents... :wee:
Warren
LetterCAM CNC Software
http://www.LetterCAM.com