Thank you for posting.
Quoting Govier's 1991 Parts Interchange Book: build code (not sales code) 011 is 1966 A-body 3:23 SG 10" brakes 7 1/4" rear end
178 is 1966 A-body 3:23 SG 10" brakes 7 1/4" rear end
Govier does not list an A body 8 3/4" rear until 1967 and the build code then is 614 non SG and 615 SG w/ 10" brakes. Doesn't mean there was none, just it's not in his book.
I have no idea why the same rear in 1966 A-bodies would have different build codes for the apparently same rear end. Perhaps Mr. Grovier amended a later printing if error were made.
Go figure.
Also FYI, "pinion" under build code was the speedometer pinion gear #, not the rear end pinion or ring gear diameter.
