Different tags around widget titles

I can edit my functions.php file to change the code around my widget titles, but how can I get the titles to use <h3></h3> on a text widget, and the default <h2></h2> on the rest? The reason I’m doing this is because my pages all have a different image in the sidebar, which I’m doing via a basic img tag in the text widget, and using the widget_logic plugin to show the image on the correct page. I don’t want a title to appear above the image, but I do want the title to appear above the blog archives, recent posts, etc. I could take out the title on the text widgets, but I have so many pages that it’s confusing to see which widget goes with which page. If I could change the titles above the images to h3 instead of the default, I could use css like h3 {display:none} to hide them. Thanks for any help.