- Revised valve angles and locations to reduce cylinder wall shrouding and improve flow - Redesigned combustion chambers to accommodate the more centrally located valves - Uses same valves, valve springs, retainers and standard 7/16" stud mounted roller rockers as Ford Racing 429 Cobra Jet cylinder heads. Requires new pushrod guide plates (M-6566-SCJ) and new pushrods, M-6565-P460 or R460 - Standard Cobra Jet intake and exhaust manifolds bolt on - Current valve covers fit - 2.200" intake valve, 1.76" exhaust valve - Flows approximately 330 CFM intake and 225 CFM exhaust - 72cc combustion chambers - 290cc intake runner, 148cc exhaust runner - 25-50 HP increase over Ford Racing aluminum Cobra Jet heads depending on displacement and camshaft - The best street/strip Ford big block cylinder head on the market today! - Uses Motorcraft AGSP series spark plugs - NOTE: If replacing Ford Racing or production Cobra Jet heads, new intake valve notches are required