Unexplainable Transmission Stutter... help?

You need to get a vacuum gauge and tune with it. Those plugs are pig rich except for maybe one of them. The suggestion to tune the enrichment circuit on the carb is a good one. You need stiffer step up springs. And it looks like you may have a vacuum leak. Yes you can have a vacuum leak at many, many different locations. Makes no difference if the ported vacuum line to the carb is plugged or hooked up to the distributor.