I don't think you have all your facts correct and I don't think you have a need to limit the current in any way. The fact is when you start any car there are hundreds of amps flowing from the battery to the starter motor for a brief period, so I don't think your amp gauge is reading starting motor current, but rather just the alternator output current once the motor is running at normal RPMs at idle or higher.
The fact that you have a new alternator that has a higher output current capacity then the original alternator, does not mean that anything in the car will automatically start drawing more current, load resistance determines actual current that flow not the capacity of the voltage source, the alternator when the motor is running, or the battery when the motor is not running.