NO. Isolated field started in '70 and they were still "round back." "Square back" started ?? 72? 73? not sure. Square back generally are better alternators. You can use the isolated field ones on 69/ earlier simply by grounding one field
YOU MUST CHECK every "rebuilt" you buy as the darn things often have ONE FIELD GROUNDED, either purposly or "accidently" due to missing/ incorrect hardware
