four barrel 318

For a mild street build with normal highway gearing I would probably keep the smaller heads for now. You Can get pretty decent performance from the small valve heads. Some like to use the 302 castings upgraded with 360 size valves but on a standard geared car I think it's a waste. You should change the cam if your going to be adding a 4BBL you can pick up 30-40 HP with a change to something bigger and better with no loss in millage. One of the mopar mags did a build up on a stock headed recon re-man 318 and got 100 hp more with small tube headers, intake and carb, and cam change. I think they used a comp 260 for the cam. The stock cam is around [email protected] with around .390 lift not much power there. You can add 75-100 HP to the stock motor and actually improve the way it drives and increase the millage. Make sure you run a small port intake that matches the heads if you can.