Speedmaster performance aluminum cylinder heads are also available for the Big Block Ford enthusiasts. With bigger displacement engines becoming more common, the need for more airflow is necessary. If you are looking to build a 400-700 horsepower engine then you should consider Speedmaster Aluminum cylinder heads. Like the rest of our performance heads we use our \"Gravity Die Cast\" process. This casting process creates a much more uniform and robust cylinder head. They also offer a smaller cross section to increase the incoming air\"s velocity resulting in improved drivability, power and economy. We have them available in as cast for the mild street applications and in Fully CNC machined for the serious enthusiast. Speedmaster CNC ported cylinder heads are machined on a dedicated 5 axis CNC machining centers to ensure accuracy and cost effectiveness. Combustion chamber, exhaust and intake ports are fully CNC machined for better flow. CNC combustion chambers offer superior control over flame travel and quench area. CNC ported heads eliminate human error and variation from port to port. INTAKE / EXHAUST GASKETS Our Big Block Ford cylinder heads are designed to use Ford Cobra Jet manifolds and headers. Due to the diameter of the intake ports, you can\"t use a standard Ford 460 intake manifold gasket. We recommend that you use Speedmaster PCE349.1009 intake gaskets. If you prefer Fel-Pro, use their pn#1231 gaskets. For the exhaust side, use Fel-Pro pn# 1420. The Fel-Pro pn# 1420 is a paper gasket, but we are currently developing a re-usable copper gasket for use with modern headers. Check with one of our salesman to see when these gaskets will be available for sale. HEAD GASKETS These heads use the same head gaskets as an OEM Ford Cobra Jet head. Because we don\"t currently make our own head gaskets for this family of engines (385 series), we recommend that you use Fel-Pro pn# 1018 on engines under 4.500\" bore. Check back often as we are currently developing a MLS head gasket to meet the needs of serious Ford performance junkies. HEAD BOLTS / STUDS As you are probably aware, the factory head bolts are 9 / 16\" diameter on BBF engines. The torque value on 9 / 16\" head bolts or head studs is 145lbs with high pressure moly lube. Start with 70lbs and tighten the head down in 25lb increments until you reach 145lbs. The part number for the Ford 460 Speedmaster Head Stud Kit is PCE279.1015. Fel-Pro makes both head bolt kits and head studkits, their part number for the head bolt kit is 155 - 4203 and the stud kit is 255 - 3701 SPARKPLUGS SPARKPLUGS Our Big Block Ford cylinder heads require the use of a 14mm thread 5 / 8\" hex, .750\" reach spark plugs. Below you will find a list of some plugs that fit and work with our heads: NGK - BCPR6ES, R5671A-7, R5671A-8 Autolite - 3923, 3924, AR3933, AR3934 Champion - RC12YC, RC10YC4, RC9YC3 Remember that you need a COLDER plug when you make more power. i.