OK, I get it! Thanks Gollum

The codes I changed if someone is interested. The template I'm using for test is versatility III but with all other templates I think it's the same.
In the /components/com_content/content.html.php:
Find around line 629:
<td class="contentheading<?php echo $params->get( 'pageclass_sfx' ); ?>" width="100%">
<?php echo $row->title;?>
<?php HTML_content::EditIcon( $row, $params, $access ); ?>
</td>
Change to:
<td class="contentheading<?php echo $params->get( 'pageclass_sfx' ); ?>" width="100%">
<h1><?php echo $row->title;?></h1>
<?php HTML_content::EditIcon( $row, $params, $access ); ?>
</td>
Now it's needed to do some changes in the template_css.css because the ENORMOUS font of all the titles:
Find around line 77:
table.sections .contentheading {
font-size: 145%;
}
.contentheading {
font-size: 160%;
}
Change to:
table.sections .contentheading {
font-size: 100%;
}
.contentheading {
font-size: 100%;
}
Find around line 186:
div#mainbody .contentheading {
font-size: 200%;
}
and change to:
div#mainbody .contentheading {
font-size: 100%;
}
Finally, make adjustments to this code to match better with the template:
Find around line 541:
.contentheading {
padding: 10px 0;
line-height:100%;
}
And change to (make adjustment depending on template but this one just work great with V III):
.contentheading {
padding: 0px 10;
line-height:10%;
}
Hope this help

and good SEO for everyone
