It has been argued that cylinder heads play the largest role in the way an engine performs. This means that selection is crucial. In the end, All Pro was chosen because they featured high-performance elements in a configuration legal for the challenge. These heads had 70/28 valve spacing, with the intake valve moved .070 inch closer to centerline, and the exhaust moved .028 inch closer to the chamber wall. This modified placement, common in the aftermarket, allows a larger valve to fit without shrouding. The rules of the game say the intake manifold must fit the heads without the use of spacers or doubled-up gaskets. This means that raised-port heads can pose a problem. All Pro anticipated this issue, and solved it by leaving additional material on the head at the intake manifold surface, allowing the customer to bolt an OEM-replacement intake manifold on. For optimum flow, the Super Victor intake by Edelbrock only needed to be port matched and to have the plenum-to-runner dividers smoothed.
Many engine build-offs reward the highest horsepower and torque readings produced at any rpm. Because of this, much of the curve gets ignored. Common to nearly all engines, Judson's 400 had a dip in torque. Judson believes this 40 lb-ft drop between 3,000 and 4,100 rpm is one of the things that lost him a First-place finish. The winning 403 Chevrolet built by BES exhibited a mere 10 lb-ft dip between 3,200 and 3,800 rpm. Judson used a COMP camshaft with 244/252 duration (at .050-inch lift) with a .370/.370-inch lobe lift, while BES used a 252/258 duration, and .367/.372-lift camshaft. This is larger overall, and helped BES to achieve the higher peak of 673 hp, but without the torque dip. Judson experimented with a larger cam, and found in his case, it made the dip worse. The rest of the valvetrain was composed of Jesel 1.8:1 offset rockers, popular because they accommodate the pushrod's relocation away from the intake port. This gives the runner a more uniform, unrestricted shape. They are also offset effectively for the 70/28 valve spacing. Judson shares that he is very happy with the complete Jesel shaft-mounted offset rockers, but would like to try the 1.9:1 intake rockers as BES did in 2007.
"Much of it is a game of who can keep the cylinder pressure up without detonating," says Judson. Being bound to the low 91-octane fuel requirement, Judson helps control the problem of detonation with the MSD Digital 7. He can control the spark advance throughout the range by setting the distributor to a higher-than-desired advance, then pull timing out as required. It is widely known that peak torque occurs at peak cylinder pressure, so timing needs to be pulled out up to that point, and then added as torque drops, since cylinder pressure follows.
In addition to requiring an OEM replacement-style intake manifold, the competition mandates a direct bolt-on header without an adapter plate. Judson's team used a relatively large primary-tube Hooker header at 1 7/8 inches. He may step down this figure to battle the torque-drop problem.