1970 Ford Fairlane 500

AFR Cylinder HeadsIf clothes make the man, then the heads make the engine. These AFR 205cc heads are based on their popular 165cc and 185cc heads, the only difference is that the intake ports are larger and the exhaust ports are raised .125 inch. They also use premium bronze-manganese valve guides for low friction, tighter fit, and durability. On the other end are ductile-iron seats, so any type of fuel can be used. The rocker bosses are extra thick and feature steel thread inserts. The valve spacing and angles are stock, so any popular valvetrain will bolt on, with the exception of rail-type rockers.

The Bumpstick
When choosing a camshaft, it's important for it to work well with the cylinder head as a combo. Stiff springs with a mild lobe profile will wipe the cam lobe, but springs that are not stiff enough will cause valve float. When we ordered our AFR heads, we gave them our cam specs so they could install suitable springs. We ordered the rest of our gear from COMP to ensure it would work together. Choosing the cam profile was the hardest part. It was tempting to go with a radical stick to nail a big peak number, but we wanted to ensure that the car still had good low- and mid-range power, and that it was fun to drive on the street. After asking for advice around the Internet, and from Scott at Reincarnation, we came up with a 236/240 duration at .050, .555-/.576-inch lift, 110 LSA hydraulic roller camshaft from COMP (PN 35-426-8, $255.95). This should make good power at the track and be a blast to drive around town.

The AFR's 60cc combustion chamber has been milled to 56cc for our application. A .024-inch thick 4cc cut (to 56cc) is all the straight milling that's allowed. A 46cc chamber is possible if you want to go the angle-milling route. You can also see the stainless 2.080-inch intake and 1.600-inch exhaust valves. With our 56cc chamber and a negative 19cc dish piston, we should end up with a 10.9:1 compression ratio (assuming a .040-inch thick head gasket). The heads also have AFR's nitrous port. "The nitrous exhaust is simply a stronger flowing exhaust port," Tony explains. "Its benefits can be realized on any application, especially if properly cammed to take advantage of it. It allows the end user to run a single-pattern cam (or slight forward split) with an N/A engine without sacrificing any peak or after peak power. The fact the customer can run a tighter spread allows the engine to make more torque and horsepower across the lower and middle part of the curve. A smaller spread on the valve events also helps smooth idle and increase the streetability of the package due to less overlap."