Pentium Porting
It's the 21st century, and some things still haven't changed. For instance, the majority of cylinder-head modifications are still carried out with a carbide cutter and sanding rolls in a performance machine shop. This manual operation is time consuming and a dirty job. About 10 years ago, with the advent of Computer Numeric Controlled (CNC) machinery and computer automation, some ingenious hot-rodder stuck a set of cylinder heads into a CNC machine, programmed a cutting table, and watched as this wondrous machine whittled away power-robbing sections of the cylinder head.
Power Heads has been successful with all kinds of Ford cylinder heads, both old and new. It can run its CNC program on vintage castings (or any Ford casting) to increase airflow and performance.
Power Heads' vintage 289 castings, like the ones we used, come fully assembled with performance valvesprings, 1.94-intake and 1.60-exhaust valves, hardened exhaust seats, and screw-in studs for an adjustable valvetrain. Basically, it's everything you want to do to your vintage cylinder heads for the rock-bottom price of $795 a pair. Power Heads set us up with its standard 289 cylinder head package, which included gasket-matching the ports and hand-blending the openings.
Power Heads' 289 cylinder heads come out of the box ready to go. It's a good idea to run a tap through all the bolt holes, and wash down the heads with carburetor cleaning spray and compressed air to remove any cardboard dust or shipping material. The heads are prepainted black, and will accept all factory accessories. Best of all, once these babies are in place and painted, no one will know the performance upgrades inside. | 
Power Heads checks each casting for cracks or problems before CNC-machining starts. The first step is to surface the cylinder heads. This ensures the gasket surface is flat and gives the surface the proper finish for optimum head-gasket sealing. The CNC machine then enters into various programs to machine the intake ports, exhaust ports, guide areas, and so on. Each step is a different program on the CNC machine. | 
The valve package is the largest you can fit into a small-block Ford OE casting, and even then the fit is extremely cozy. With valves this size, fly-cutting your pistons will probably be required, so double-check before assembling your 289. |
11 With the valvetrain installed and adjusted, we could install our Extrude Hone factory 4V intake. John placed the Fel-Pro intake gasket on the cylinder-head mating surface and secured it with a few dabs of gasket adhesive. Silicone sealer was used around both water-jacket ports at the front and rear of the cylinder heads. | 
12 Like most any engine builder would, John threw the cork end gaskets into the trash and instead ran a serious bead of silicone sealer on the end rails of the block-to-intake mating surfaces. Once the silicone cured, excess could be trimmed away before painting the block for that stock look. | 
13 Our intake manifold came back from Extrude Hone just a few days before our installation photos were taken. We had just enough time to bead-blast the manifold and clean and tap all the bolt holes. Our AMK engine master hardware kit from NPD saved our bacon many times during the buildup of our 289. It was nice to open a package of new, clean hardware instead of trying to clean (or, in this case, find what we needed) and reuse 38-year-old hardware. |
14 An original Ford replacement crankshaft damper from NPD was bolted into place. We also installed our remanufactured cast-iron water pump from NPD. We used the AMK fasteners for the water pump, though some bolts were too long at that stage of the game, like the one shown here. John simply threw some washers under the head of the bolt and taped it off (it's supposed to be a natural finish). | 
15 All of the external engine parts that were supposed to be painted blue were installed, and the water pump and water-neck fittings were masked off. John threw a pair of shop covers on the cylinder heads and laid down several light coats of Ford Corporate Blue to finish off the paintwork. | 
16 We'll save the concours detailing for another article; however, we had to dress the engine with a few items to get the engine ready for dyno-testing and break-in. We picked up our heater-hose fitting, temperature sending unit, bypass hose and clamps, and Cobra-lettered valve covers from NPD. |