For service and to replace a broken stud on the assembly line, Ford used a screw, 376560-S100 8-18X3/8L truss head 3/8dia. This applies to 64 thru 68 and I see no reason not to use the same repair for 69 and 70. The bad news is that it is not available from AMK, but with the spec listed you might find a replacement.
(I'm across the street for pizza.)
Jim