IL WTB eventually OEM 68 327 INTAKE MAN & CARB

[GerhardH]

Assembling engine: 04-24-1968
Assembling Car: 05/1968
Set in service 06-29-1968

If you have a look on the protect-o-plate is clear stated that the carburator
was a CARTER : C

Here a statement from a known Carburator Expert:

The numbering rules for Rochester carburetors have a lot of exceptions. One common one is for trucks, where the an odd number is often used for both standard and automatic.
This is the case in 1968 where the number 7028213 is used for a 327 in a truck, regardless of transmission. However, in passenger cars in 1968, 7028213 were used for 327 standard transmissions and 7028212 was for automatics. It would be incorrect to have a 7028212 on an automatic equipped 327 truck since the Rochester manual from the period lists only 7028213 for trucks. GM used Rochester and Carter-produced QJets interchangeably. I don't believe that the carburetor source was recorded anywhere when the vehicle was built. However, it is probably true that certain dates are more likely to have one or the other, but this information hasn't been collected anywhere that I know of and exists only anecdotally.

Carburetors designed for manual transmissions will normally run lean if used on the same engine and automatic transmission. The carburetors for automatic transmissions are generally slightly richer in the idle circuit to compensate for the fluid coupling losses in the torque converter.