Regulator conversion to 1970 late model charging system question

Hah! Looking in my Crystal Ball and mumbling a few phrases I'd say we're looking at a '69.

I agree 100% with Dana. If there is nothing wrong, leave it alone.

An alternator only supplies the power that is needed.
It takes about 5 amps to run a '69. About half flow to the ignition and the other half to power the field.

After starting, the alternator also has to recharge the battery. That can be 10 or 15 amps very briefly and then less.
Look at the ammeter and observe if it swings from slight discharge during starting to charging once its running.
When its done recharging, the needle goes to zero.