One of the easiest ways to get increased holding power from a clutch is to increase the surface area, right? Well, the factory NV4500 featured a 12-1/4" diameter facing, where the later 6 speed NV5600 jumped to a 13" so wouldn't it make sense to upgrade to a 13"? Sure it does! Valair offers this upgraded clutch kit specifically for 5 speed NV4500's that converts it to a 13" clutch disc and features a heavy duty spring hub that can handle up to 400 horsepower, while still offering up easy engagement for daily driving and towing.
MORE INFORMATION: Organic/Organic: Typically considered a "stock" clutch both in the way it feels, and in cost. Aftermarket organic clutches are generally better than the OEM clutch you get from your dealer. This is due to the better quality materials used and the quality of the manufacturing process and QC.