* IH 266: This is a 266 cubic inch (4.36 liters) inline six-cylinder engine, producing around 130-140 horsepower. It was the most common engine choice for the 1600 Loadstar in 1966.
* IH 304: A slightly larger 304 cubic inch (5.0 liters) inline six-cylinder engine, generating around 155-165 horsepower. This was a more powerful option, often found in heavier duty models.
* IH 392: A V8 engine with a displacement of 392 cubic inches (6.4 liters). This engine was only available in the 1600 Loadstar for a limited time and produced around 210-220 horsepower.
To be completely certain about the engine in your specific 1966 International 1600 Loadstar, you should look for the engine identification number, often found on a plate attached to the engine block. This number can be used to determine the exact engine type and specifications.
