Sigh...
87A is the normally closed circuit, so IGN1 Run power flows through it to 30 as the 12V source. When power is supplied by IGN2 in Start, it powers 86 which activates the relay and sends power through 87 which is normally open and closes when the relay is activated. This way there is 12V at terminal 30 in both Start and Run.
oh right, i didn't see that he wanted to keep all of the factory ignition (ballast and all that). figured since he was doing EFI he was doing a different ignition too.
seems using a relay in the fashion you described would work well.
