Im suprise everyone overlooked the underdrive pulleys they give 4-6 hp. Then theres the timing gears if you adjust the timing a tad, but i wouldnt recomend messing with the time unless you know what you are doing. As far as the cams i would go aftermarket there is a lot you need to look for in exchanging cams its not just slap them on and instant light speed, overlap,duration and lobe seperation Figure what it is you lookin for, research it before you do anythin look up books i know there still exist a library somewhere if not hit up the book shops like barnes and knoble and brookes theres a series of HpBooks that talks about all sorts of car topics from Nos to crappy gas you put in to your car. Theres a book that i have and that i often use for refrence its Honda/Acura Engine performance by hpbooks this is good book for beginners its the one i started with and still use to this day check it out and youll see