* 6.00" rods: These are generally found in stock or mildly modified engines. They represent the more common, original length. They offer a good balance of strength and durability for everyday driving and moderate performance.
* 5.700" rods: These shorter rods are typically used in high-performance engine builds aiming for higher RPMs. Shorter rods allow for a higher piston speed at a given RPM, and can contribute to increased power at the top end of the rev range. However, they generally put more stress on the connecting rod bearings and piston pins.
In short, the choice between 6.00" and 5.700" rods is a design decision based on the intended use of the engine. The shorter rod sacrifices some bottom-end torque for increased potential top-end horsepower. You wouldn't typically find both lengths used interchangeably in the same engine family from the factory.
