For what I know all formula s barracudas from 1965-1967 had commando engines with 4 barrel carb set up due to the high compression domed pistons for higher horse power this type of model had.
This 273 commando that my car has is a matching number to the car.
There were no "matching numbers" until 1968 for some models and 1969 for all models. Casting numbers and casting dates is all the early cars had. "Date code correct" is a more correct term.