Are you looking for big torque and horsepower number? Only AFRÍs 225cc aluminum cylinder heads will provide you with exactly that. With the largest intake and exhaust runner volumes for our in-line Ford line up, these are the ultimate for NMRA Renegade or Hot Street classes. With 2.080 intake valves and 1.600 exhaust valves these heads move massive amounts of air. Combustion chamber volumes of 58cc accompanied by 80cc exhaust ports which are raised .375 higher than stock. AFRÍs new 225cc is the perfect choice for 347 through 427 CI windsors engines operating between 4500 to 8500 rpm. Our trademark 3/4î thick cylinder head deck makes them ideal for heavy nitrous or blower applications. Note: 2.080 valves will require aftermarket pistons notched for valve clearance. Ford Small Block - 225cc Race Ready CNC Ported Heads - 58cc Combustion Chambers, Stud Mount Rockers - Bare Heads