D300 - No TC - 500/4 AFS

Here the clamp is fully engaged

Note that the plate is half out of the clamp.
A friend with a D700 and 500/4 AFS VR reports that he can not mount this configuration in a balanced mode. There are significant differences in weight and overall length between those two models, and likely the 500/4 AFSII has some other (unknown to me) balance point.