These Dart Iron Eagle S/S cylinder heads are the perfect way to squeeze a little bit more performance out of your street engine. They are designed to offer many of the features of other high-end cylinder heads at a more affordable price. Dart produces these heads from premium, high-density cast iron with extra-thick decks for durability and power potential. These heads feature precision-cast 165cc intake ports and heart-shaped combustion chambers that are designed to produce great airflow without expensive or time-consuming porting. The hardened exhaust valve seats are fully compatible with unleaded fuels, and the multi-angle intake and radiused exhaust seats further improve flow, maximizing power. Dart utilizes screw-in rocker studs that won't pull out, even under heavy use, and the machined valve cover rails eliminate possible oil leaks. All you have to do is choose which combination of combustion chamber volume and valve size will best complement your engine, and whether you want fully assembled, bolt-on heads or bare, ready-to-build castings. Dart Iron Eagle S/S cylinder heads produce great throttle response and gains in low-to-midrange torque, just where you need it, for your street hot rod, musclecar, or pickup.