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14 Here are the parts responsible for the gear ratio change--on the right is the 4R100 and the left is the standard C6, both are interchangeable. The 4R100 uses a six-pinion planetary, while the C6 uses either a four- or three-pinion one. The 4R100 planetary holds more power, but the C6 is acceptable for milder applications. The pictured parts also contribute to the Second-gear ratio turning from the standard 1.40:1 ratio to 1.54:1.