I'm sure that this is also a feature in Pulse version 3 but I could not find the version 3 documentation on the Pulse website to verify it. So I have tried it myself before writing this answer.
The following text is a modified version of the Pulse 4 Blocks documentation :
Super blocks are like regular blocks with two differences. First the WYSIWYG editor is replaced by a plain text editor. This editor will not adapt the content of your file while saving. Second, you can have code such as PHP and JS in the block. To create a Super Block, just create a new block and prefix the name with 'sb_', for example 'sb_date'.
Use for instance as content : <?php echo date("l jS of F Y h:i:s A"); ?>
Integrate this Block as normal on a page with its full name (sb_date.html)
Good luck (Veel succes )