Are you saying remove all of the GC cards, just leave
the slots blank?
Yes, from the slots that are designed to take the core memory or its
controllers (I assume, given you have special backplanes, there are
boards with the core planes on, and more boards with the XY drivers
or the sense/inhibit logic on).
Do you have a diagram of where the core boards should go. If so, are
there slots in the backplane left over. What are those 'extra'
slots for?
-tony