Brian,
Look at your second picture. It has a hex drive in the middle with two threaded 3/8-16 ends. The stud was used to attach the battery ground wire to the I-6 engine for AT cars only, then the clip for the cooling lines. I believe the stud's part number is 380818-S8 and is documented in the Ford Car Parts Illustrated section A71 pg 6. I made the assumption that the part number is for use in I-6 engines. I haven't found a part number for the V-8 version. It has a 7/16-14 end for the ground to engine. The bracket has a basic part number of 7C008 which is not serviced (fabricate at dealership). This looks like it was a running change implemented in 1966 and carried thru to at least 1968. I'll let Jeff find some pictures.
Jim