If they had front drum brakes even 73 up they are still small bolt pattern. Its the 73 up disc brake cars and even the 318 got a 7 1/4 unless manual or HD rear was ordered then it should have a 8 1/4, along with the 340 and 360 cars got the 8 1/4.
The pre 73 A-Body cars are all small bolt pattern but the axles were either 7 1/4 or 8 3/4 those years.