* 2.3L 4-cylinder: This was a common, smaller engine option.
* 2.8L V6: A more powerful V6 option.
* 3.3L V6: A larger displacement V6 than the 2.8L.
* 5.0L V8: This was the larger displacement V8 option, but still smaller than later "5.0" Mustangs. (It wasn't necessarily called a "5.0" back then, but that's its displacement.)
To know the exact size of the motor in a *specific* 1979 Mustang, you'd need to check the vehicle's documentation (like the original owner's manual or the vehicle identification number (VIN) decode) or look at the engine itself.
