The Carter is set up for the "AFB" flange configuration, with 2 additional holes in the "Holley" configuration. The flange is plenty large to mill 2 additional holes so it will fit the "Holley" configuration. Have seen many of them that have been modified with the extra 2 holes (total of 8).
The issue with the 9400 is that Carter made the last one about 1980; they are very much in demand, and fairly pricey.
Jon.
Just thought of something, you mention it having two sets of holes, that means it would most likely bolt right up to the Aussie Intake, as it too has two sets of holes that are Holley 4160 pattern.
