The pushrod V8 is back in the Mustang engine bay. It is not the 302 or the 351 Windsor. It is the 7.3L Godzilla. Ford designed this iron block powerhouse for the Super Duty truck lineup. Enthusiasts immediately saw the potential. It is massive. It is heavy. It makes torque like a freight train. For Fox Body owners, it represents the ultimate displacement upgrade without the massive width of a DOHC Coyote.
The hardware is there. The aftermarket has caught up. You can now buy the parts to bolt this truck engine into a 1979–1993 Mustang. It is not a weekend project for a novice. It requires specific hardware and a clear plan. Here is the technical reality of the Godzilla swap.
Size and Dimensions
The Godzilla is a big engine. It is roughly 23.5 inches wide at the valve covers. For context, a 5.0L Coyote is nearly 29 inches wide. This narrow profile is the Godzilla’s greatest advantage. It fits between the shock towers of a Fox Body with room to spare. You do not need to notch the towers. You do not need to delete the power steering rack.
The challenge is height. The 7.3L stands 33.5 inches tall. This is significantly taller than a 351 Windsor. The stock truck intake manifold will not clear a factory hood. Even with a cowl hood, clearance is tight. Most builders swap to a low-profile intake manifold from Indy Power Products or Brian Tooley Racing. These units shave vital inches off the top.
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The Foundation: K-Members and Mounts
You cannot use a stock K-member for this swap. The oil pan and mounting points are completely different. Companies like Team Z Motorsports now offer Godzilla-specific K-members for the Fox platform.
These K-members do more than just hold the engine. They move the steering rack and adjust the engine height. This is critical for hood clearance and ground clearance. Most of these units require a manual steering rack or a specific power steering pump relocation kit.
Oil Management
The factory 7.3L oil pan is a massive front-sump bucket. It was designed for a truck with a solid front axle. It will not clear a Mustang K-member or the ground.
Indy Power Products offer low-profile swap pans. These pans are shorter and feature a rear-sump design. This allows the engine to sit lower in the chassis. A lower engine improves the center of gravity. It also helps clear the hood. You must use a matching oil pickup tube with these pans.
Power Potential and Megazilla
The standard Godzilla crate engine makes 430 horsepower and 475 lb-ft of torque. It uses a cast-iron block and aluminum heads. The internals are robust. It features a forged steel crankshaft.
For those who want more, Ford Performance released the Megazilla. This version is a dedicated crate engine. It produces 615 horsepower and 640 lb-ft of torque. The Megazilla uses forged-steel H-beam connecting rods and Mahle forged-aluminum pistons. It features CNC-ported heads and a larger 92mm throttle body.
The Megazilla is not street legal in many jurisdictions. It is intended for off-road and racing use. It provides a reliable 600+ horsepower foundation without the need for forced induction.
Electronics and EFI
The factory Ford PCM is an option. Ford Performance sells a Control Pack specifically for the 7.3L. It includes the ECU, harness, and accelerator pedal. This is the simplest way to get the engine running. It retains the Variable Cam Timing (VCT).
The community preference is shifting toward Holley EFI. The Holley Terminator X Max is a popular choice. It offers superior tuning control for modified engines. There is a catch. Most Holley systems do not natively control the Ford VCT phaser.
Most builders use a VCT lockout kit when running Holley EFI. This locks the camshaft in a fixed position. You lose the efficiency of variable timing. You gain the simplicity of a traditional pushrod setup. For a race car, this trade-off is often worth it.
Drivetrain Compatibility
The Godzilla uses the same bellhousing bolt pattern as the 4.6L, 5.4L, and 5.0L Coyote. This is excellent news for transmission choice.
- Manual: The Tremec TKX or T56 Magnum are the standard choices. You will need a modular-pattern bellhousing.
- Automatic: The 6R80 and 10R80 are popular swaps. They require a standalone controller if you are not using the Ford Control Pack.
You will need a custom-length driveshaft. The engine position varies based on which K-member you choose. Always measure after the engine and transmission are bolted in.
Why Choose Godzilla?
The Coyote is a high-revving masterpiece. The Godzilla is a torque monster. The iron block handles massive boost. It is simpler to work on. It fits better in the engine bay.
The weight is the main drawback. The 7.3L weighs roughly 580 pounds. This is about 130 pounds more than a Coyote. You will need to adjust your front spring rates. The extra weight is a small price for 445 cubic inches of displacement.
The Godzilla is the new king of the big-inch swap. It brings modern tech to the classic pushrod formula. The hardware is ready. The power is there.
Learn more about Ford Performance parts at Mustang Mag
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