On the parts sheet right at the top, item "1" - retainer - 10 Required.
they are #8 Chrome screws, Pan head, about 1 1/4 long, all these trucks usually have the holes striped out, have to dolly holes flat again and hope screws tighten, I have on occasion put screw in hole and hold a screw clip under rad support to tighten them, this can be done through the park light holes and the gap between the support and rad with overflow bottle removed, the screws holding that down has the same problem quite often, these are sheet metal screws and not 1/2 bolts they don't need 1oo ft lbs of torque, just snug.