in my opinion... the first thing i would do is replace your head gasket
if it's still sealing well at the moment you should be able to get away with ripping the head off, new toyota hg, new head bolts torqued to 72ft lbs and slap her all together
then at least you know you are set for power (i was gonna say boost but you don't mention if you are turbo or not hehe)
then start with Intake, exhaust
let us know if ur turbo or na.. that'll tell you the next things you can do
