Your other alternative would be a smaller alternator pulley. Changing the crank pulley would change ALL of your pulley ratios, so that might mean all new pulleys. If everything else works fine changing the alternator pulley would be easier.
Are you running a v-belt or serpentine? March makes serpentine alternator pulleys down to 1.676, even with your current crank pulley that would be 3.13:1. V-belt down to 2.125, so that would be 2.5:1. Not all of them may fit that alternator but there are options.
