253/308 carbs and aircleaner Q's

[Absinth]

I've got 3 Rochesters are the numbers are as follows

17057294 0748
17057294 2367
7041282ZF 1271

Also have a LH exhaust manifold 7424983

Whats your thoughts with these numbers??

17057294 0748 Body cast in 1977.... carb assembled in March 1978

17057294 2367 Body cast in 1977.... carb assembled in July 1977

7041282ZF 1271 Body cast in 1971.... carb assembled in May 1971

All three are off manual cars.