Sometime in 1966, a stud was used instead of a bolt for the battery ground on small block V8 engines with an automatic transmission. In general, the arrangement was: block; external tooth lock washer; battery ground cable; alternator ground cable; stud; AT cooling lines bracket; jam nut (Ref: Ill sect A71 pg. 6). This is Ford service assembly criteria. It implies that the battery and alternator were grounded first, then the AT bracket installed. I, personally, do it this way: block; AT cooling lines bracket; stud; battery ground; alternator ground; external tooth lock washer; jam nut. I do it this way as I've replaced more battery and alternator ground cables then AT cooling brackets. The real answer lies whether, on an AT engine, the alternator and battery ground were installed before the transmission. This is speculation, the alternator and battery ground installation could have included the AT cooling line bracket, which is close to the 1965 and earlier method that used a bolt. (I also use an additional external tooth lock washer at the block, it's the EE in me, always redesigning.)
Jim