Find out what cam you have, I hear a guy on hear can port and match some mean heads for a great price *cough* Harold . That right there will open up some freebie hp. Other things would probably be like..Do you have Full exhaust? Timing on par? Freshen up the block. I really don't know much so i am probably missing some things!

oh yeah! Get a stroker kit then! or a power adder - low boost though! lol don't want you cracking the stock block ;P