When using Site Sync you could specify which exact items you want to synchronize. If you are using this static link in a content block, for example, you can select all other content blocks, except for the one you don't want to change (refer the attached image for more information). Unfortunately, at the moment, there is no option to exclude specific data while synchronizing.
Hope this would help you.
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items