Post & Edit Pages at Level 2

Hello,

Believe me but I absolutely need to give permission to post and edit pages to my level 2 authors. (I can’t up them to level 5 because of security reasons).

I have search since 2 hours and I find nothing on this particular point. I have hack the user_can_edit_post_date function in functions_post.php, but there isn’t here other permission functions.

Where are the functions or conditions to change the “Pages permissions” ? Someone can guide me ? ??