Like I mentioned before. If you are only doing heads or only doing cam, I think the cam will do you the most good. If you are thinking about adding the other later you might as well keep what you have and build a engine with a purpose. Like me and my 70 318, It has dual exhaust and a Pertronix. I have a LD4B and a AVS2 to put on but I haven't yet. I also have some 68 340 manifolds and will replace the exhaust. Half of it is till the original single split and made into duals. Get the intake off I am staring at the cam and the 50,000 mile old original timing chain might need replaced. Hell, I might as well pull it and build it with the Speedmaster heads I have stored in the basement. Or better yet, get a 360 Magnum. Where does it end? There is no good answer!