Thanks Tim! I went ahead and ran it, it works! The black clip to engine ground and the green clip to coil (-) negative terminal that is also wired to the distributor.
So a follow-on question, the shop manual says to drop Idle to 500 RPM and then run the vacuum test. But in terms of regular Idle setting (day to day operating) , seems like 800-900 RPM is a much smoother, stable idle. Do you have a 235ci in any of your trucks? Just curious, what do you set the Idle to?
