Check for 12V+ with key on at the power wire for the HEI.
The black wire goes from the junction block on fender to the connector block on the firewall. Mine has been removed, so not sure how important it is.
Regarding NSS mentioned by previous poster. You can disconnect it and check both sides for 12V+ when key is in start position.
Alternately you can make a jumper harness for it. Just be sure to fix it before you start daily driving it.
