Voltage regulator/rectifier and power pack/ stator questions

I have a 1991 150 hp model GLEIS (60 degree) all original. I bought it new and except for water pumps nothing has been replaced. I have three questions first should the voltage gauge read 15 volts when running above 3500 rpm and then settled to 13.5 volts after you have run for a while at 3500 rpm? Second if the voltage regulator/rectifier is bad is there a problem finding one that works with the stator and power pack that both have the black sleeve. I noticed the regulator/rectifier that they list now does not have the purple wire and third is it true there were problems with the black sleeve power pack and stator that originally came with this motor? If I were to change the power pack and sensor do I also have to change the stator? Sorry to be so wordy but this is keeping me up at night.

Anybody have any info on this?
Thanks

1991 had a 100Volt coil pack that is why you have to stay with the PP for that motor. To change to the newer 50 volt system you need to change stator/PP and coils.

Championman do they still sell the power pack for this motor? Is it the one with the blue sleeve?

Yes to both.

Championman if it running good with no problems should I still change to the blue sleeve power pack or is it ok to continue with the black sleeve power pack? Where there problems with the black sleeve power pack that could damage my motor?

No internal damage I would think.

Championman thanks for all your help I really appreciate it.