Originally Posted by McGrath
Honestly some headers would work nicely and then a 3.4 or 3.3 also. Even though that is out of your price range it would give you a nice bump in power. If you're looking for more power under $500 how about an Intense FWI? Or maybe a electric water pump not the most bang for the buck but definitely in your price range. Or even pick up a good used Gen 3 M90 and port and polish it your self.
I saw the electric water pump and thought that was an option too. How difficult are those to install? Should I increase my car'* voltage to compensate? (Caspers V-Plus Volt Booster for 3800 Series II Engine) Will I need to buy a shorter belt?