Other then the most common changes like intake, carb and camshaft is that the clevelands exhaust ports are too big and have poor velocity which makes the exhaust useless under 7000rpm. They make a block off plate that bolts between the head and exhaust and closes off 30% of the port. This creates more velocity and creates scavenging in the exhaust system. I would use 1-3/4" exhaust headers with this system. Another area that would help is going to a full roller rocker arm. Hope this helps a little..