* 2.73: A relatively high gear ratio, often found with larger engines and automatic transmissions, favoring highway fuel economy.
* 3.08: A good compromise between performance and fuel economy. Common in many configurations.
* 3.36: Offered more acceleration, but at the expense of fuel economy. More likely with six-cylinder engines or some V8 combinations.
* 3.55: A relatively low gear ratio prioritizing acceleration and towing capacity. Often found with performance-oriented options.
* 4.10: A very low gear ratio, primarily found on higher-performance models or those intended for towing heavy loads. Rare on a typical El Camino.
To know the exact ratio for a *specific* 1966 El Camino, you'd need to:
* Check the vehicle's data plate: This plate (often found on the driver's side doorjamb) may list the axle code. This code can be deciphered using a Chevrolet parts catalog or online resources to determine the gear ratio.
* Look at the differential tag: The differential itself usually has a tag indicating the gear ratio. You'll need to access the differential to see it.
* Inspect the differential: You can physically count the teeth on the ring and pinion gears and calculate the ratio, though this requires expertise.
Without information specific to the individual vehicle, it's impossible to give a definitive answer.
