DB cleanup. Removing CCK database tables after Upgrade

Hi there,

I've migrated all my CCK fields from D6 to D7. Everything works as exspected. The cck content migration was successfully executed.
Before I am going to launch the new site I'd like to clean up my database. I've successfully uninstalled most of the old D6 module. However as I can see in Phpmyadmin there are still some leftovers from CCK. Do you recommend deleting them?

I've compared both databases from D6 and D7. These tables seem to belong to CCK:

cache_content
content_field_test_next
content_group
content_group_fields
content_node_field
content_node_field_instance
content_type_page
content_type_story

Are there any references to the old CCK content types? Do I still need them?

Thanks for your help