Hei conversion troubleshooting

Squareback alternators using an older mechanical VR with 1 field output must have one of the alternator fields grounded to the case/body/batt - however you want to wire it. The other will go to the points style VR. True electro-mechanical 68ish VR's will have 2 rods exposed on the back. If its flat with 2 straps, it an electronic retrofit.
"...You can use a dual field alternator in an single field (pre 1970) car by using a jumper on one field to ground, but you can't use a single field alternator on a dual field (1970 and up) car..."