The 2.3-16 is lighter, shorter, wider and lower than the 2.3. While the automatic is nice, once you've driven the 5-speed you'll want it. The engine is just half of the 16 valve. A transplanted 16V engine in a 2.3 won't give you the full 16V experience. Sell the 2.3 and buy a 2.3-16. Just do it. You will not regret it.