Mark Houlahan
Tech Editor, Mustang Monthly
June 7, 2016
Photos By: Air Flow Research

It’s not always about the Coyote or pushrod stroker engines here at Mustang-360. No, we’re fans of old school displacement too and there’s nothing like the sound of a Ford big-block with a healthy cam. Perfect for everything from Fox body Mustangs to vintage Mustang street cars, even kit cars and street rods, big-blocks have a lot of street cred and visuals going for them. While the FE-series big-blocks seem to get all the press, Ford’s 385-Series (429 and 460) are serious torque monsters and have been used in everything from Lincolns to F-series trucks and are still plentiful salvage finds today.

Air Flow Research has been a leader in performance cylinder head design for decades with many Ford engine offerings. Just announced is its new Bullitt line of performance cylinder heads and intake manifolds for Ford’s 429/460 big-block engine family. The Bullitt cylinder heads are available in 270cc, 285cc, and 300cc runner designs, all with optimal valve locations and revised 14-degree intake/8-degree exhaust valve angles (which will require custom pistons or fly-cutting your existing pistons). Exhaust ports are located in the stock location to work with your favorite headers, but an optional .250-inch raised exhaust port is available as well.

AFR’s new Bullitt cylinder head for 429/460 Ford big-blocks are built with premium parts from ARP, PAC, and more.

These new Bullitt cylinder heads are an “as-cast” design with CNC-ported intake and exhaust ports (50 percent on 270cc, 100 percent on 285 and 300cc heads). The A356 aluminum casting features a CNC-ported combustion chamber with bowl blend (80 percent on 270cc, 100 percent on 285 and 300cc heads) and a five-angle valve job as well. The included spring package is available for hydraulic or solid roller applications and features PAC Racing springs, 10-degree locks and retainers, ARP 7/16-inch studs and 3/8-inch guide plates. Valve sizes measure 2.250-inch on the intake (2.300-inch on 300cc head) and 1.760-inch on exhaust. All heads are available in 75cc or 88cc chamber configurations. The 270cc runner Bullitt head is capable of over 700 hp and 390 cfm at 0.650-inch lift.

To compliment these new cylinder heads Air Flow Research has also cast up some nice single plane intake manifolds. Available in both 4150 and 4500 carb flange designs, the single plane manifold features an improved port design and are direct bolt-on to complement the power making abilities of the new Air Flow Research Bullitt aluminum cylinder heads.

AFR provided us with flow charts on the various head offerings in the Bullitt line. Here is the chart for the 270cc head at 28-inches of water.
Next up is the 285cc head and we have flow numbers for both the stock and raised exhaust port options.
Our last flow chart is for the 300cc version of the Bullitt cylinder head.
The all new intake casting was designed to complement the new Bullitt cylinder heads, but since it uses stock mounting locations it can be used with your current engine if you’re looking for just an intake upgrade.
AFR tested all three runner sizes in back to back dyno tests on the same big-block, a 521cc Ford Performance short-block.