It was the Power Bond balancer rubbing on the Indy cast front cover causing drag so it would not idle. Couldn't see any witness marks on the cover but putting masking tape on the cover and turning it over with everything bolted in place revealed the culprit. The guy who assembled the motor had clearanced the cover but didn't go wide enough.

Take away is use a long snout ATI balancer (regular snout also interferes) in the first place. In this case I will get a 0.093 thick spacer from ATI (#916370) to put behind the PB balancer and re-do the belts / crank pickup alignments. Hope the thrust surfaces on the crank / bearing face are still OK and the clearance hasn't gotten too big. But hey, at least the rings had some load on the first runs.