I am not familiar with the Injen windshield washer mod. Pictures may help. The scoop I am talking about goes behind the lower grille.
I think the ported throttle body only adds a couple HP but it is relatively inexpensive. Also, check the other post on LFX mods as a pulley upgrade is mentioned that I am not aware of:
http://www.camaro5.com/forums/showthread.php?t=339237