* 240 cubic inch inline-six: This was a workhorse engine, a popular choice for its reliability and fuel efficiency.
* 302 cubic inch V8: A more powerful option offering better performance.
* 351 cubic inch Windsor V8: This was a larger, more powerful V8, typically found in higher-spec models.
* 390 cubic inch big-block V8: A very powerful engine, less common but available in the F-100.
To know the *specific* engine in a particular 1968 F-100, you'd need to check the vehicle's documentation (like the original owner's manual or a vehicle identification number (VIN) check).
