4age Head Mod Please Help!!!!!!!!

I have a 88 mr2 with a blown engine , so i found another 4age. While i have it out i am trying to give it some more bottom end. I have owned one before and they are way doggish under 4000. rpm. anyway heres my ques. Would i get any more hp by decking the head? If so how much and if not here is my mods and any suggetion would help. i have 1 week before the mechanic has to install it.

Trd header
trd exhaust
hks degreeable cam gears
web 262 cams
cold air intake

thanks T