If that alternator part number is what you have then it is not a stock unit for a 1964 year model. With the alternator part number you provided it has an internal regulator it can be bench check at an auto part store. If it works there then it the wiring in your truck. To use that alternator there is no external regulator and the wiring will need to be modify to work with the alternator. You will need to buy a small harness kit. Here is some instruction for the mod:
https://www.motortrend.com/how-to/gm-cars-alternators/
Here is a conversion kit for installation of the SI alternator:
https://www.ebay.com/itm/202275380018
I would not recommend using a one wire alternator, it can cause more electrical problems if your harness is original.
On my truck (64 1500) I had a wire broke off of the ignition switch that prevented the alternator from turning on.
Good luck.