[Injuneer]

March makes two different sets.... a "performance" series where both the crank pulley and the alternator puller are underdrive units. Then they make a "power & amp" series that includes an underdrive crank pulley and an overdrive alternator pulley to help the alternator satisfy the demands of a big audio system, etc.

There is not much power to be gained with these, and using an overdrive alternator pulley is just giving back some of the small power savings.

The March units are also "sandwich" type.... you pull the stock damper/pulley off the hub, put the new pulley behind it and bolt the stocker back on the hub. The better way to do it is with the integrated underdrive pulley/damper from ASP. Less rotating mass.

In theory, the stock damper/pulley should not need the "puller" to get it off. But after many years of rust buildup, a bit of persuasion is often needed to break the pulley loose from the hub.

Its also a bit difficult to get the alternator pulley off. Its hard to hold the alternator from turning when you use a wrench on the nut that holds the pulley on. Using an air impact gun often works, but it can still be a difficult job.