Ford Godzilla Swaps Made Easy


Ford Godzilla Swaps Made Easy


The big news in Blue-Oval land has been the tidal wave made by the arrival of Ford’s “Godzilla” V8 for 2020. This 7.3L, 445ci pushrod motor is a major step away from Ford’s overhead-cam modular approach to engines. It delivers a massive 475 lb-ft of torque in stock condition – just what’s needed to pull monster loads in full-size Ford trucks. Horsepower is rated at “only” 430, but once unencumbered by a stock cam, 600 horsepower is achievable with more enlightened configurations. Remember, this beast is 445 cubic inches. A 560 lb-ft torque peak is almost a given with a cam, intake, and exhaust mods, and it’ll whip out 600 hp without too much effort.

Of course, it took no time at all for Ford fans to consider this a prime engine swap candidate, especially for traditional muscle cars. The perennial issue with employing Ford’s Modular engines for swaps is width, especially for DOHC engines like the Coyote. But while the Godzilla engine is significantly narrower than a DOHC Mod motor, it offers its own challenges to those looking for a big-inch swap into the broad range of Mustangs, for example. Let’s look at the challenges facing the Godzilla 7.3L swapper and several new Holley components that produce real-world solutions to these issues.

The stout torque and horsepower figures of Ford's 7.3L Godzilla engine make it irresistible for swappers, but its hefty overall dimensions can make it challenging to shoehorn into anything but big vehicles like this '67 Ford F100. One of the main culprits is the tall stock intake manifold and its sharply upturned throttle body.

Midsize Monster

Like its original sci-fi namesake, the Ford 7.3L Godzilla is big – but not as massive as you might think. As you can see on this chart comparing bore spacing and deck height, the 7.3L Godzilla actually slots in the middle of Ford’s most popular pushrod V8 engines. Bore spacing determines overall engine length since that’s the distance between the cylinder centerlines. Wide bore spacing creates a longer engine, while a taller deck height creates a wider engine. Combining these two specs determines overall engine length and width.

Engine Bore Spacing (inches)Deck Height (inches)
Ford 302W4.388.206
Ford 351W Early4.389.480
Ford 351W Late4.389.503
FORD 7.3L GODZILLA4.539.650
Ford 390 / 427 FE4.6310.170
Ford 429 / 4604.9010.320

The Godzilla’s 4.53-inch bore spacing and deck height of 9.65 inches positions this new pushrod V8 slightly taller and wider than a 351W but more compact than a Ford FE or 460. And beyond the raw specs, the Godzilla also has another advantage over legacy Ford big-blocks when it comes to engine-swapping. “The Godzilla engine is easier to fit headers and exhaust manifolds on than either the FE or 460 engines,” says Jim Dralle of Holley. “The exhaust manifold flange on the Godzilla’s head is recessed inside of the outer row of head bolts instead of on a vertical flange outside the head bolts as on the FE and 460 engines.”

All that said, there are three critical drawbacks to the 7.3L Godzilla that need to be addressed before an effective swap can be performed. The big talking points are the ridiculously deep factory oil pan, the wide OE accessory drive, and the tall factory intake manifold with its up-turned throttle body.

The 7.3L Godzilla reinforces the old adage of “no replacement for displacement.” Even in pure stock Ford trim using the more conservative OE dyno correction factor, the Ford 7.3L is capable of making over 400 lb-ft of torque at 1,500 rpm. Peak torque is a heart-warming 475 lb-ft while peak power is only 430 at 5,500. In a less restricted application with a cam, Holley intake, and headers, the 7.3L could get close to or exceed 600 hp.

Oil Pump and Pan

Taking a bottoms-up approach to the Godzilla, Holley recognized that the factory oil pump placement and its deep oil pan are the first major impediments to swapping success. The Godzilla’s OE oil pump is actually located in the middle of the engine and is powered by a jackshaft driven off a secondary gear-and-chain assembly underneath the front timing chain cover. This system is designed to reduce the length of the suction pipe on the oil pump, but it unnecessarily adds to both engine length and oil pan depth.

The Holley solution is to relocate the oil pump on the crankshaft snout under the front cover, much like other modern engines such as the GM LS and the Chrysler Gen III Hemi. This move eliminates the cumbersome jackshaft oil pump drive, which produces a much shallower front oil pan that can snuggle the deep-skirt block much lower into any engine compartment. The new Holley front cover was designed to use either the factory Ford jackshaft or the Holley oil pan system with the pump located underneath the cover. The expanded Holley kit (PN 20-320) includes the oil pan and front cover, plus the remaining critical components such as the oil pump, pickup, and all required hardware.

The expanded kit’s new Melling gerotor oil pump attaches to the inside of the front timing cover with bolts that are torqued only after the cover is in place. Another advanced feature of the Holley cover is its dedicated O-ring seal around the entire perimeter where it meets the block. The Ford OE cover merely uses a thin strip of RTV. The internal connections for coolant and oil are sealed with O-rings in both covers.

Holley's oil pump setup replaces the stock mid-mounted, jackshaft-driven pump with a Melling gerotor unit that mounts under the front cover like other contemporary V8s, such as the GM LS and Chrysler Gen III Hemi. Another advantage to the Holley cover is its O-ring seal instead of the OE version's bead of RTV. Holley engineers also made pressure-lubing the engine easier: On the passenger side of the pan, there's a fitting where a pressurized fill tank can push oil through the engine to pre-lube it before initial start. Similarly thoughtful is the Holley unit's simple external access to the oil pressure relief spring.

Beyond sealing, the Holley pump arrangement also offers the additional benefit of external access to the oil pressure relief spring. So, if after installation there’s a need to adjust the relief valve spring pressure, the Holley cover makes this process quick and easy.

There are multiple options within the combinations of factory and aftermarket parts, so you should study the parts lists carefully. For example, there are some applications where the factory oil pan and pump system could be retained. In these situations, the basic Holley front timing cover kit could be applied since the cover is designed to accommodate the factory oil pump drive system.

Shop Holley accessory drive and oil pump kits for Godzilla now

The new front-mount oil pump setup is available several ways, to tailor the unit for your unique needs. Regardless of which configuration you choose, Holley's kit comes complete with everything you need, including brackets, fasteners, gaskets, and seals. Also included is the slick star-shaped tool seen here that installs the front timing chain cover seal using the crankshaft bolt to press the seal in place. The specs show the depth of the Holley pan as 6.25 inches, which is nearly 2 inches shorter than the OE pan. This offers significant ground clearance advantages.

Accessory Drive

Another big hurdle to overcome when swapping Godzillas into Mustangs and other space-challenged vehicles is the engine's stock accessory setup, which sits low and wide on the engine, adding considerable width to the overall package. Holley has addressed this problem with its high-mount accessory drive kits, which move the accessories toward the top of the engine and places them closer in to narrow things considerably.

Rather than force buyers into a one-size-fits-all setup for the accessory drive, Holley offers its new Godzilla accessory drive system à la carte, much like the Burger King ads where you can “have it your way.” The accessory drive choices start with an alternator-only application that offers four choices for alternator output, ranging from 105 to 150 amps. If power steering is important, that’s available using a bolt-on integrated reservoir, pump, and pulley assembly. Then if you want to sweeten your 7.3L package with air conditioning, Holley has that covered as well with a compact A/C compressor. All these components are designed to be driven by the original Ford harmonic balancer/crank pulley, or an aftermarket unit can be used if desired.

If you’re considering any of these accessory drive systems, it’s a smart move to call up the specific part number application and read the online instructions that come with computer-generated images showing all the details necessary concerning the installation. Reading and studying these instructions will often answer questions and remove much of the doubt about which system is best for your application.

The new high-mount accessory drive package offers multiple options to run just an alternator, or alternator and power steering, or a complete system with alternator, power steering and a top-mounted A/C compressor.

This entire accessory drive adds a mere 6.75 inches of length from the factory Ford front cover mounting point, which is shallower than the depth of the Ford harmonic balancer. Plus, the system can perhaps be best described as high and tight. The A/C pump is moved to the upper passenger side of the engine, which makes frame rail interference much less likely. The same is true with the driver-side mounting of the alternator and power steering pump. Holley put plenty of thought into this regarding Ford engine compartments that are often space limited.

Take-out engines and Ford’s Godzilla crate engines using the stock timing cover require the use of an ECU-controlled alternator. To add further to the list of options for Godzilla fans, Holley offers an alternator bracket kit with or without a stand-alone alternator that doesn’t require ECU control, which makes engine swaps much easier when retaining the factory front cover.

Shop Holley's full line of Godzilla Accessory drive kits and components

Holley's drive setup moves the accessories from the factory low-and-wide location to more of a high-and-tight arrangement that reduces potential frame rail interference. The Holley unit is also shorter lengthwise: Measured from the block face mounting point for the timing chain cover, it's only 6.75 inches to the water pump snout.

Low-Profile Intake Manifold

Holley's mid-length cast aluminum intake is a tremendous problem-solver when it comes to Godzilla swaps. The factory Godzilla intake is tall, with an upward angled throttle body. Together, these issues make it an awfully big lump to cram under the hood of anything smaller than a full-size pickup. In contrast, the Holley low-profile Godzilla manifold is far more swap oriented, intelligently eliminating the steep 45-degree upward tilt of the factory Godzilla throttle body. Instead, it's angled downward 10.5 degrees, for 55.5 degrees of overall difference – a significant benefit when trying to fit the engine underhood in tight confines.

Beyond that, the Holley manifold will also accommodate three different throttle body combinations: the factory 80mm 7.3L drive-by-wire (DBW) version, the cable-driven ’86-’95 Fox-body style, or the 92mm 2020-2023 GT500 version with an adapter. The manifold’s throttle body opening is 92mm but can be easily ported to 95mm if necessary.

The new manifold is 2 inches lower at the rear and 3.5 inches lower in the front. The throttle body is much more effectively placed, because it angles down 10.5 degrees instead of the 45-degree upward slant of the OE unit. Holley also offers an aftermarket alternator bracket kit for the OE cover to make the charging system easier to control. Not only is the factory alternator located in an ungainly position but it must be controlled via the factory ECU. For most engine swaps, an aftermarket alternator is much easier to control and is relocated much closer inboard with the Holley bracket. However, this re-positioned alternator will not clear the Holley low-profile intake manifold.

While just these improvements are certainly worth the price of admission, the manifold itself has been massaged to lower its profile by 2 inches at the rear and 3.5 inches at the front compared to the OE design. The combination of all these factors makes this a smart approach.

But to add another incentive, the runner length has been modified to maintain midrange torque while enhancing top-end power. Holley’s early dyno testing reveals that the new manifold can maintain average torque within 3 lb-ft of the factory numbers between 2,500 and 6,200 RPM in an otherwise stock configuration. Average power is down only 1 hp when using the GT500 throttle body compared to the stock 7.3L configuration.

Note that these numbers are averages using a stock camshaft. By shifting the manifold runner length to enhance peak horsepower, it’s common to lose torque at engine speeds below peak torque. It’s clear that when the 7.3L is enhanced with a more aggressive camshaft, the peak and average numbers will be far more impressive. Finally, the lower portion of the manifold is removable to allow porting or nitrous fittings.

Shop Holley's low-profile Godzilla intake manifold in natural or black-powdercoat finish

The shorter Holley intake allows significantly more underhood clearance, with minimal penalty to performance. In dyno testing, torque was down only slightly compared to the stock manifold. Optimizing cam specs to suit this manifold will likely regain all of that power and then some.

Terminator X Max for Godzilla

The latest addition to Holley’s ecosystem of Godzilla parts is the Terminator X Max EFI. This proven system gives you complete control over a wide range of parameters, greatly simplifying the job of swapping a Godzilla engine into any classic vehicle. Using the Terminator X Max for your Godzilla swap solves a lot of problems – you won’t be burdened with figuring out how to adapt the Ford factory ECU into your vehicle, and you’re not stuck with the factory tune settings, which may or may not work with your particular combination of induction, ignition, transmission, and other variables. Terminator X Max lets you optimize your settings to work flawlessly, no matter what your specific combination is.

The system has four inputs – 12v, ground, 5v, and frequency, allowing you to add pressure sensors, or activation triggers for things like nitrous activation or a trans brake. Although the Terminator X Max won’t control low impedance injectors, the system’s high impedance injector drivers will safely power most OEM injectors. And the built-in 1-bar MAP sensor is perfect for naturally aspirated or nitrous engine combos. The Terminator X Max easily accommodates drive-by-wire throttles when paired with an appropriate drive-by-wire kit, OEM throttle bodies, and correct throttle pedals.

A big part of Terminator X Max’s vast capabilities come from the included software; it’s widely acknowledged by novices and experts alike to be the best available for running an EFI system. The program’s advanced tables include four 1D tables; one 1D per-gear table; four 2D tables; and one 2D per-gear table. These can be used for any custom tables you could possibly need – for example, a flex fuel sensor offset table, or a custom oil-pressure safety table. The software also has extensive boost control features, including boost vs time, boost vs gear, boost vs RPM, boost vs speed, and boost safeties. Complementing this capability are powerful nitrous control functions, giving you options for a single channel of wet or dry, progressive or non-progressive, rich/lean safeties, and target closed loop AFR.

Besides being the most capable aftermarket ECU available for this engine, Holley Terminator X Max for Godzilla is also the easiest to install and set up. The included 3.5-inch handheld touchscreen features a Calibration Wizard, which allows you to easily build a base tune for your engine. The system’s Real-Time Fuel Map Learn feature configures itself automatically, so there’s no guesswork in setting up your base fuel table.

Shop Holley Terminator X Max for Godzilla now

Further simplifying setup, the unit has onboard diagnostic LED indicators for a wide range of functions, including ECU power, engine run, wideband status, TPS calibration, crank signal, and cam signal. This allows you to identify engine issues immediately. Further enhancing this capability is the system’s integrated data logging features, which make diagnosing and troubleshooting your engine practically effortless.

The Terminator X Max for Godzilla is just one more example of how Holley is simplifying Godzilla engine swaps, making them easy for DIY car builders of any skill level. When combined with the Holley Godzilla accessory drive, oil system, and low-profile intake manifold, this comprehensive collection of components opens the door for the Godzilla to power just about any classic machine you can imagine. And that’s the most exciting part – the sky is the limit on what kind of builds can be dreamed up around this beautifully burly powerplant.


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