I'm more confused now.
In Musclecarkid's post he said that "no 96X 97X 98X 99x 4557s have the GG suffix[90x was about the cutoff on 4557s to receive the GG code]]"
and Eric explained the date decodeing as 98x is August, 99x is September: then no September of 69 4557 carbs should have the GG which mark says his 4557 carb has.
Did I misunderstand what is being said?
Sorry if this is hijacking the thread.