you can bolt a piece of angle metal to span across the grill & out on to good metal picking up both the bolt at the crack and the one opposite. looks like you need through bolts out of an old motor to replace those rusted up ones though.
Thanks everyone. I'll have to come up with a solution. I think the angle iron on top is a good idea. I may weld the crack shut, this would stop vibration that may contribute to elongating that weak spot. (kinda like a windshield crack)
I can't tell from the picture - has the condensing fan motor been replaced with one that is heavier than the original? If so, that has contributed to the crack. The metal has trouble supporting the OEM motor, and a heavier one just exacerbates the situation.
(I got to use that cool word in the last sentence!)