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Can I realistically expect any gains in power with the cam and head work without the bigger exhaust?


Not too likely as the cam and head mods basically push more air into the cylinder- therefore you need to upgrade the intake/exhaust to get that air in and out of the engine. Otherwise you're going to be wasting a lot of that power in exhaust backflow. What kind of head mods are we talking? Oversized valves, port/polish job, shaving the bottom of the head?? All except the port/polish should be paired with an upgraged intake/exhaust.