Considering ND is Japanese, and used on a number of Japanese vehicles as well (and you know how those guys can get...) you probably won't have a problem. Besides, it's not like your pully is half the size of the one it's replacing.
54m/m dia = ~170m/m circumference
57m/m dia = ~179m/m circumference
Difference? About a 5% overdrive, should be.
Why for are you overdriving your alternator? Trying to get more output, or trying to get full output at a lower RPM? If the latter, you're on the right track. If the former, you're going to want a bigger alternator anyhow (voltage output can be as much a matter of the alternator's armature and field windings as anything else - higher current units have more windings, usually using a slightly smaller gage of wire so it fits in the same case.)