Edelbrock E-Tec 200 heads have 200cc rectangular intake ports and 78cc exhaust ports. They outflow other similar aluminum heads by 10% on the intake and 17% on the exhaust, making power up to 6500 rpm. 64cc combustion chambers produce approximately 10.2:1 compression when used with flat-top pistons in 350-inch engines. E-Tec 200 heads come with 2.02" intake and 1.60" exhaust valves.