This is the engine that theoretically...
This is the engine that theoretically started it all when it comes to swapping bullets in late-model (Fox and up) Mustangs. The 351W is a natural upgrade for 5.0 'Stang owners who want the torque and horsepower increase that comes with additional cubic inches. Disregard the oil pan in this photo. A Fox-specific pan and pickup tube are required for installation in '79-'93 'Stangs, as well as a flexplate/flywheel or the harmonic balancer (351W is 28oz balance versus 50oz internal balance for an '81-'95 5.0), intake manifold, accessory bracket, distributor, and exhaust headers. Most of the pieces that make up a 351W/Fox Mustang swap package can be purchased from FRPP.
Let's take a brief look at some of the engines for the swaps we're looking at in this report. First, the 351W shares the 4.00-inch bore size and taller deck height of 9.500 inches of the 302s found in Fox Mustangs. A Windsor's block features thicker webbing in its lower half for increased strength, and its crankshaft has a bigger main and rod journals than the smaller engine's crank. In addition to the obvious 49ci gain right off the top, installing a stroked Windsor opens the door to multiple displacement options and insane horsepower/torque gains over an original 302, especially with the addition of a power adder.
While it would've been a cool option, a 351 Windsor was never offered as an available engine for '79-and-up Mustangs. But in 1995, Ford produced a special run of 250 race-bred, Cobra R 'Stangs that were equipped with 351W engines.
The 4.6 DOHC Four-Valve Cobra engine is an aluminum piece (pre-'03-'04) with a 3.55-inch bore and steel-crank and a 3.54-inch stroke. The deck height for Cobra blocks is 8.937 inches. There are two different power/ torque ratings for naturally aspirated Cobra engines. For model years '96-'98 the ratings are 305 hp/300 lb-ft; for '99-'01 they're 320 hp and 317 lb-ft. Thanks to the excellent airflow of their cylinder heads, adding a Kenne Bell Twin Screw blower to either engine will ramp up performance nicely, but sourcing an '03-'04 Cobra bullet and adding the "Kenne," a centrifugal blower, turbo, or nitrous would be a better move. The later snake engine is founded on a cast-iron block and features a steel crank with forged-steel rods. With its Eaton blower, it makes 390 hp and 390 lb-ft of torque.
Four-Valve InTech engines found in Lincoln Navigators have been around since 1999. These engines are popular with the Mustang crowd because of their forged-crankshaft lower end and aluminum cylinder heads. Despite their good cranks, Navi engines aren't blessed with the strongest rods in the world (fracture-split powdered metal), so their horsepower threshold is about 600 at the flywheel. One of the major pieces necessary for a 5.4 swap is a good intake manifold. Experts say the intake from a '99-'01 Cobra is the way to go, so make sure you have a lead on one before starting the project.
This pre-'03-'04 4.6 non-supercharged...
This pre-'03-'04 4.6 non-supercharged Cobra engine is popular among Fox owners who want to adapt new-school technology to their old-school 'Stangs. It's also well-liked among 'Stangbangers with '96-'98 GTs, six-cylinder cars, or 5.0-powered SN-95s who feel the need for more modular power. While the swap has a few dicey moments from a Two- to Four-Valve perspective and certain GT accessories require reconfiguring or direct replacement with actual Cobra parts, the swap is relatively plug and play. Dropping this bad boy or any modular V-8 into a six-banger or last-gen 5.0 'Stang is quite the project, as it involves an extensive wiring-harness change, a throttle cable and linkage change, a revamp of the air conditioning lines, and so on. It shouldn't be attempted unless you have a complete donor Cobra to use as a parts source.
An interesting point: As luxo-SUV engines go, 4.6s found in Lincoln's Aviator feature an aluminum intake manifold with variable-length runners, similar to FRPP's FR500 intake. Aviator 4.6s also use the same Four-Valve, twin-cam cylinder heads as Terminator and Mach 1 'Stangs and are good for 302 hp and 318 lb-ft of torque. While flywheel performance for Navigator 5.4 engines isn't overwhelming-260 hp at 4,500 rpm-the 350 lb-ft of torque they pump out at only 2,500 rpm make them a desirable swap option for any-year 'Stang.
The last two specialty engines that we think are great, albeit elaborate, choices for engine swaps are the bullets found in the Ford GT and the Shelby GT 500. The GT's engine is an all-aluminum, dry-sump Four-Valve that's influenced by a Lysholm screw-type supercharger. It also features dual fuel injectors for each cylinder and oil squirters for the piston skirts. It's rated at 550 flywheel horses and 500 lb-ft of torque.
The '07 Shelby GT 500 uses an iron-block DOHC 5.4 with an Eaton Roots-style blower and air-to-liquid intercooler. These pump out 500 hp and 480 lb-ft of torque.
In the same spirit as the 351W-powered '95 Cobra R, Ford produced a handful of specialty Cobra R 'Stangs in 2000 that were powered by Four-Valve 5.4s.
The new swap trend favors modular engines. For those who need numbers to compare against, here's an overview of the crankshaft horsepower and torque that stock 'Stang Two-Valve engines ('96 to present) produce:
1996-1997: 215 hp/285 lb-ft
1998: 225 hp/290 lb-ft
1999-2004: 260 hp/302 lb-ft
We'd be remiss if we didn't mention that the all-aluminum, single-overhead-cam, Three-Valve 4.6 engines of S197s should be considered for swapping into pre-'05 'Stangs. The engines feature variable camshaft timing and make a reported 300 hp and 320 lb-ft of torque.
 As engine swaps go, the 5.4...  As engine swaps go, the 5.4 Navigator engine can be called the modern-day 351W. This is the bullet that SN-95 and New Edge 'Stangbangers are choosing to install as more-than-suitable replacements for their stock 4.6 Two-Valve engines, once again adding more cubic inches, horsepower, and torque. Navi engines are trick additions to Fox 'Stangs, and aftermarket companies are slowly but surely catching on and developing parts to ease swaps to the big modular. |  There's not much that needs...  There's not much that needs to be said about either of these two bad boys. The Shelby GT 500 (left) engine and the motivator of the Ford GT super car are slam-dunk winners of the "coolest swap" award. |  We're aware of two Fox projects...  We're aware of two Fox projects that include these bullets-one is our own editor's Fox 500, and the other is being done by none other than Donnie Walsh Jr. See 5.0 News for more info on that project. |