At
http://yoursite.com/forum/admincp/vbioptions.php? choose which box you want to be custom. Then select from the corresponding drop down menu Custom Box x (x being the custom block # you want to use). Make sure the rest of the settings are correct and hit save.
Then in the Style Manager find the template vbindex_customblock_x (again, x being the custom block # you want to use).
Find
Code:
<strong>Custom Block $box</strong>
Replace that with
Code:
<strong>Block Title Here (example: About Us)</strong>
Then find
Code:
<div class="smallfont">Block $box Content</div>
Replace that with
Code:
<div class="smallfont">Whatever you want to be shown in the main part of the block</div>
Save it and you're done! Hope this helps.