I believe Sharon is talking about the whole housing wobbling in the engine block.
I have seen this in the past and have not come up with a good explanation for this.
I have tried changing distributors with the same wobble after.
The only thing I could come up with at this point is that the drive gear on the cam is not running concentric giving uneven side pressure in the distributor gear.
The only other idea I have is that the pilot hole in the oil pump that holds the lower shaft of the distributor is worn so it is not supporting the lower end of the shaft.
It seems I have seen this with a new pump also so that seems unlikely.
