When I received my "merlin motor" ready to go, it had a .714 lift cam and 268 deg duration @.50. I went to a smaller, Better Builder,He changed the cam and corrected the valve train geometry. Installed larger seats to match the 2.25 valves already installed and pocket port and port matched the heads to the intake.The cam was smaller,roller,and had a cast gear so I didn't need a bronze distributor gear. I picked up 7-10 mph. I would consider a nice port job to match the intake, and a good pocket port to see your cam change make a real world difference.