Initial testing was done on this '99 cobra engine. The DOHC mill sports a paxton, but it was disconnected to simulate what the results would be on a stock-type engine. This DOHC powerplant features mildly ported heads and intake, Oliver rods and Ross pistons designed to make only 8.9:1 compression. Second Street Speed originally designed the rockers to increase durability power, but were rewarded with substantial power gains. Despite the lowered compression, horsepower figures were very close to Ford's advertised numbers, but with the rockers installed the engine gained as much as 40 hp.