Freschie,
There is no direct answer to your question. If the resistor is in the tweeter pad or baffle step, changing the value will change the volume of the tweeter, so your speakers character will clearly change, If it is impedence compensation, it will change how much your impedance peak is lowered, depending on frequency, you might or might not notice, if it is in a notch filter, it would change how much peak is reduced and also would be audible. As stated by others, without taking considerable measurements, I would suggest that you follow the original design.
I hope this helps, Tim