One of the biggest intimidation factors for fitting the modular Engine is the size of the engine compared to all but the big-block applications of the past. The engine is fairly wide compared to pushrod applications, which can present challenges for engine installation. The way Ford has designed the engine mounting can also be a challenge with an earlier engine bay. In some applications, the front suspension determines how the engine is mounted in the engine bay, and items such as superchargers may force the position of the engine toward the firewall in early first-generation Mustangs. Items such as a brake booster can interfere with the wider DOHC heads. The alternator location on some engines is down low and can conflict with the frame rails of some vehicles. In this chapter I discuss the items you need to address to physically make the modular engine fit in the engine bay.

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Your engine must fit your car, and so I’m going to talk about the things you need to do to fit it in the engine compartment. The modular engine is generally wider and taller than traditional pushrod engines, so fitting the engine in some chassis can be a challenge. You may need to make changes to your suspension system to fit the engine in your project. Items such as oil pans, steering systems, and braking systems can also interfere with the engine mounting. This section may be covered in detail in other chapters, but you need to consider these items before you get the engine in the engine bay.

Engine Dimensions and Weights

One of the reasons people avoid modular conversions is the belief that the engines are much heavier than traditional pushrod engines because they are bigger in some dimensions. Weights and dimensions vary depending on engine size, accessories, and component material. Items such as aluminum versus iron blocks and superchargers lead to great variability. The above chart is provided as a comparison of the 4.6 and Coyote engines to traditional pushrod engines.

Frame versus Unibody

Most small performance cars are unibody construction or constructed with a unitized frame, and this means the sheet-metal panels of the body are welded together to form a functional frame and the structural rigidity of the vehicle. Trucks, full-size vehicles, and most older GM and Chrysler products gain most of their body strength from a traditional ladder frame, and the body simply mounts on top of the frame. It is much easier to modify a full-frame car than a unibody because cutting away the structural metal (like a shock tower) severely affects the integrity of the body strength.

In general, Ford used frames on midsize and larger vehicles and trucks, and these cars had fairly large engine compartments, so the physical dimensions of the modular engine don’t come into play as severely as with the smaller cars. Vehicles such as Mustangs, Fairlanes, Falcons, Mavericks, and later T-birds used a unibody construction, so making room in the engine bay may be necessary. The biggest hurdle to getting the modular engine in these cars is the bulging shock towers. They severely limit the ability to install these engines. Most of these vehicles must be modified to accept an entirely different suspension.

Front Suspension Systems

Most classic Ford passenger car suspensions are a double A-arm design with a coil spring and shock absorber. On smaller Ford vehicles, the shock is typically mounted on the upper control arm and to the frame in the bulging shock tower. This takes up vital space within the engine compartment that is necessary for the engine and wider wheels. On intermediate- and full-size vehicles, Ford mounts the shock to the lower control arm and then to a mount point near the frame. This frees space in the engine compartment and helps with the efficiency of the shock system. The closer the lower shock mount is to the lower control arm ball joint, the more efficient it is in transferring movement to the shock.

In 1969, Ford introduced the Pinto and incorporated a compact suspension system into it that was later installed in the 1974–1978 Ford Mustang IIs, which shared the same platform as the Pinto. This suspension system uses an uneven-length double A-arm design with the shock and spring mount between the two control arms, unlike the earlier Ford with a shock tower that mounted the shock above the upper control arm. This allows for a compact suspension, which has become popular in the street rod world because it can be adapted to many different frames. And because the suspension sits low under the frame, it allows for larger engines to fit into engine bays not originally equipped for them. The suspension also makes use of a rack-and-pinion steering system, which works better than the older worm and sector gears. The aftermarket has developed this suspension system for nearly every kind of chassis, from street rods to unibodies, and with that has come tubular suspensions, coil-over shocks, and large brake conversions.

In 1979, Ford began installing MacPherson strut suspension systems in some of its vehicles and, as a result, the upper control arm was eliminated and the suspension simplified. Most current systems are still strut designs with a reverse-mount lower control arm.

You need to carefully choose the suspension system for your car and modular engine drivetrain. Even if a different suspension system fits in your car, it doesn’t necessarily make it the best option. Most aftermarket systems are designed for the original architecture, and sometimes that changes the way the original designers intended the suspension to function. For example, the shocks are usually mounted at an angle defined by the arc curve of the suspension and how it travels. The angle of the shock also affects its efficiency, and the more severe the angle of the shock, the less efficient it becomes. If you fit a new suspension system and change the shock angle, the system may not work as well as the original system it is replacing. Just because it fits doesn’t mean it is better.

If you are building your car for any kind of performance driving, particularly with competition in mind, your first question for the manufacturer of choice is, “Who’s winning with your stuff?” If you plan on taking your car to the track, use what people who are winning use on their cars. Time and again I hear about people installing the latest fad suspensions on their cars only to find that it doesn’t actually work any better than what they just removed.

At this point you may be asking, which system is best for my conversion? There is no single answer because there is no conversion for all applications and you need to realize that suspension systems are designed to work within specific parameters and at different costs. A road racing suspension may not be great for a car driven daily, and a suspension that is made for compact installation may not handle as well as the original system.

Guidelines for Selecting the Right Suspension

1. What is the overall intended use for the vehicle? As I mentioned in the introduction, the application or use of the vehicle determines the needed suspension. Example: If you plan on using the car for drag racing, an independent rear suspension is not the best choice. On the other hand, if you install a race suspension on a street car, it will have a harsher ride and be less fun to drive. You need to determine the type of use before selecting a suspension system.
2. What is available for your project? Mustang II suspensions are available for many different chassis and are probably a universal choice for most builds. The Mustang II suspension is often a great choice for many street cars, but it may not be the best choice depending on your answer to question number 1.
3. How readily available are parts? Exotic systems such as Jaguar rear axles can be expensive and parts for it may be hard to find locally; a system designed from parts available at your local parts store may be a better alternative. For example, the Ford Cobra brake calipers for the rear are the same from 1994 to 2004, and in the United States they can be purchased at any Ford dealer or auto parts store. This may be a better choice than a custom-made caliper that has to be sent back to the manufacturer for rebuild. But it may not work as well.
4. What is your budget? Cost may be a big factor in what the final use is. For example, least expensive is to convert your original first-generation suspension to handle the modular conversion, next expensive is the Mustang II conversion, and on the high-end is the Griggs Racing conversion.

As with building a modular engine, my goal here is not to make you an expert on suspension and handling, but to help you get the engine into the chassis. Whether you are building a hot rod, pro touring car, dragster, or other type of car, a book is available about how to design and build a suspension for your needs. Choosing the right suspension depends on the eventual use for your car and is something you are going to need to research to get right for your project.

Early Mustang Suspension

The majority of modular engine swaps are into first-generation Mustangs, so I discuss them here. A lot of this information covers Cougars, Falcons, Fairlanes, Mavericks, and other Ford vehicles with layouts similar to the Mustang’s.

The early 1965–1970 Mustangs used an uneven-length double arm suspension with a shock absorber mounted to the upper control arm. Most of the companies that sell “performance suspensions” tell you that this system is terrible. But the truth is, it isn’t that bad. Over the years I have learned a lot about the original uneven-length double arm suspension on the Mustang. Companies such as Street or Track and its ST-6873TFEKIT take everything I have learned about the original Mustang suspension and make it much better than most systems on the market for the early cars. Although the original systems exhibited bump steer, the terrible original steering gear contributes to the condition. In addition, modern radial tires are often aligned to the original alignment specifications of the 1960s, which compounds the problem. To resolve this problem, you should consider upgrading to a rack-and-pinion steering system such as the Randall’s Rack system or the Total Control Products rack-and-pinion designed to work with the original-style front suspension.

Shelby discovered that by dropping the upper control arm 1 inch it was able to eliminate some of the roll in the body during hard cornering. One of the drawbacks to this modification is that the upper ball joint can bind and wear out faster, so performance companies began building upper control arms with a revised ball joint angle to eliminate the bind when the control arm is dropped. You need to follow a few guidelines when installing the modular engine and using the original front suspension. Unfortunately, the modular engine is not compatible with the 1965–1966 Mustangs and Falcons; you need a different suspension setup because there simply is not enough room. Even with the control arm drop, the upper arms mount too far inboard to allow the engine to fit into the chassis. The modular engine exhaust and the upper control arm want to share the same space in the engine bay. You will be shopping for something else with these cars.

With the 1967–1970 Mustangs, you have enough room to install a modular engine. In 1967 Ford moved the upper control arm outward 1  inch to accommodate the wider FE 390 engines. The lower control arms were relocated to accommodate the change. All 1965–1970 Mustangs have the same frame rail width dimensions.

The FE installation was tight to say the least, and owners found it very difficult to change the spark plugs on these cars during routine maintenance. Drag racers found it unbearable but discovered a work-around. Turns out the angle of the shock and spring allows for the shock towers to be cut back to gain access to the center two spark plugs on a 390-428 engine. Ford did the same thing on the 1969–1970 Boss 429 to make room for the Boss heads.

Some 2V modular engines have been installed into Cougar and Mustang chassis by an “influence” from a tool (sledge hammer) on the shock tower. Rather than do that, you can cut the tower back to make room. With the towers cut back, the 4V engines will fall between the shock towers. There is plenty of room to reinforce the back side of the tower (which you just removed a bunch of) for strength. By lowering the upper control arm position 1 inch, you make clearance for the exhaust manifolds that want to lay right on top of the control arm bolts.

Mustang II Suspension

Originally designed for V-6 Pintos, the Mustang II suspension has blossomed into a product for the street rod industry because of its compact size and design, which adapts well to many other chassis. Hot rodders loved it for its compact size and its adaptability to frame cars, and it allowed for larger modern engines to be installed in older chassis.

Many muscle car owners adapted it as a replacement for the original suspension in some of the early Ford unibody cars because it eliminates the upper shock mount; the shock is mounted between the two control arms. The shock tower can be removed from unibody cars, which leaves plenty of room for a big, wide modular engine. These suspensions come with rack-and-pinion steering gears, which replace a not-so-good part of the old Ford chassis.

Several companies, including Detroit Speed, Heidt’s, and Griggs, have taken the basic compact design of the MII and developed it into a road-hugging, race-winning system. Griggs Racing’s designs are winning on the track and are an excellent choice for true performance vehicles.

The front clip needs to provide support and strength for the Mustang II suspension on a unibody car. As stated before, the unibody gets its strength from the sheet-metal panels welded together to create the chassis. The shock tower is a big, thick piece of steel welded to the front engine compartment panels; it adds a lot of strength to the front end. The unibody system flexes a lot, and that is why the early Mustang is known in some racing circles as “the hinge.” Taking out the towers doesn’t help with that reputation. Successful MII installers take the extra step and reinforce the area on the back side and tie things together to gain back what is lost by removing the towers.

One other point I discovered about installing the modular engine with some MII kits is that the oil pan hits the crossmember on some of the early manufacturers products. Some MII kits now come notched for the stock pans.
 

Strut Suspensions

MacPherson strut suspensions eliminate the upper control arm and allow for a simplified geometry. Used widely in front-wheel-drive cars, this suspension system has been the staple in the Mustang camp since 1979; all the new engineering is designed around it. It doesn’t interchange well into the original early chassis, though, so companies have worked around this problem to get the technology into the early cars. The Mac strut systems use rack-and-pinion steering, which also improves the handling of the earlier cars.

Fox-Body Mustangs and Thunderbirds

When installing a modular engine in your Fox-body car, you can adapt a later-model modular K-member to the early chassis. The struts are an inch shorter, allowing for extra underhood clearance. Some of the early T-birds from the Fox-body eras can also be fitted with the later modular engine K-members, making these swaps a breeze.

Other Designs

Several companies and their racing programs provide suspension systems that deliver excellent performance, as can compact designs such as the Corvette suspension systems. Many of these designs can be adapted to a variety of cars, but the best suspension choice depends on the car and its application. When I am working with a customer on an early Mustang swap, I typically recommend three systems. If the budget isn’t available for a big overhaul or the car is just to be used for mild street driving, I usually recommend retaining the original suspension.

To improve performance, I recommend replacing the stock steering gear with a rack-and-pinion system, but then you need to convert to a front sump oil system. In addition, you can select good quality Moog or TRW suspension parts. Keep in mind that some parts sold in “handling” packages are inferior quality, so stay with a reputable manufacturer, such as Moog or TRW. Once the conversion has been completed, you can upgrade to a Street, Track, or Global West suspension system at a later date and not have to change anything.

A strut system is the next step up, and Dave Stribling Restorations offers a strut conversion that incorporates all the SN-95 K-members and struts without changing any of the geometry. This means that performance upgrades from Maximum Motorsports, Kenny Brown, or Steeda swap right in. The ride quality and handling are worth the additional costs if you can afford it. Strut kits are available from Gateway Classic Mustangs for many early cars, and they have tower cutback plates that allow for the structural integrity of the towers in the chassis and room for the modular engine.

If my customer wants to go racing, I look into the Griggs Racing GR350 suspension systems. Bruce Griggs has engineered his front suspension system to handle as well as any other system out there, and his cars win.

The modular engines swap into the early Fox-body Mustangs without any K-member or suspension modifications, so any suspension engineering improvements made for the Fox platform still work.

Engine Mounts

The engine mounts consist of two parts: the engine isolators that attach to the engine and the frame mounts that connect the frame to the isolators. Polyurethane isolators are available from Energy Suspension (PN 4.1127) for installing modular engines into early Mustangs and Cougars with original suspension and into a Fox-body chassis. UPR sells a K-member (PN 2005-79-MOD-50) that bolts in to the Fox chassis and mates with the above isolators. Maximum Motorsports also sells a conversion K-member (PN MMKM21). With the exception of the Fox body, some Mustang II conversions, and some early Mustang conversions, you may have to fabricate your own engine mount system.

The good news is, the isolator mount holes have not changed on the modular engine block, so half of the fabrication has been done and you should be able to adapt one of the existing isolators to your chassis. With few exceptions, you will probably be fabricating engine mounts for your project unless the suspension builder has already done that for you. You can use one of Ford’s engine isolators, but you may be fabricating your isolator-to-chassis mounts yourself.

Motor mounts for early Mustang are available through Dave Stribling Restorations and use a 2003 GT isolator and mount in the stock 1967–1970 position. Late-model K-members for Fox-body cars are also available, as the mount is incorporated in the K-member.

Isolators

The isolators mount to the engine via a series of holes cast into the side of the block in a 100 x 80–mm rectangular pattern. Ford has used these holes for other things along the way, such as the GT500 oil cooler on the 5.4 engines.

The early-style isolator was a rubber bushing mounted fairly perpendicular to the block. With the start of the SN-197 Mustangs (2005), Ford went to a vertical isolator for the Mustang that was mounted on top of the factory K-member. Prothane makes polyurethane isolators for early applications (1996–2004) PN 6504BL and vertical (2005–2014) PN 6505BL.

Oiling System

The oil pan and oiling system is a big concern when installing the new engines in older cars, and it often interferes with other components. Most older cars have a steering system that is mounted behind the oil pan reservoir (front sump) whereas the modular engine installation uses a steering system mounted in front of the reservoir (rear sump). In Ford modular-equipped cars, the lone exception to this is the front-wheel-drive 1995–2002 Lincoln Continentals. The rear sump pan’s big advantage is that under hard acceleration the oil doesn’t roll up and out of the reservoir, potentially starving the pump and bogging down the crankshaft. Even in cars already set up for rear sump oil pans, you may need a shallower pan and extra capacity, depending on the application. Moroso makes a low-profile road pan that works well in low cars such as Factory Five Racing roadsters, and Canton Racing makes a conversion oil pan and pickup to convert the rear sump systems to front sump to clear rear-steer steering systems, as well as drag and road racing pans for rear-sump installations.

Oil Filter and Clearance

On many installations, the oil filter hits the frame, particularly on unibody applications, because the oil and coolant passages exit in the same area on the earlier 4.6 and 5.4 engines. Ford changed this on the 5.0 Coyote engine and the inlet for the coolant is located at the front of the block on the driver’s side. Ford pushrod engines have the oil filter mounting base cast into the block. However, modular engines use a bolt-on adapter, and this adapter can vary, depending on the application. Most of these designs place the oil filter out much farther than the older pushrod engines.

Several options are available if you run into this problem. Ford used a 90-degree oil filter adapter (PN F4UE-6884-BA) on some installations, such as the Police Interceptors and some vans. It is tapped and threaded for the metric modular oil filter. Ford Performance sells the same adapter (PN M-6880-M22), only the FPP unit accepts a standard FL1-A or 3/4-16 threaded filter.

Most manufacturers that made oil filter outlets for the more common FL1-A filters are now tapping them for the modular 22-mm threads because the mounting pad is the same. These can be used for a remote oil filter mount and external oil coolers using the original oil filter mounting pad.

Oil Coolers

Ford used radiator coolant to cool the engine oil. A circular intercooler was mounted between the filter and the inlet of the block. On some earlier engines, the intercooler worked in conjunction with the inlet design of the coolant passage next to the oil passages. On later 5.0 engines, the coolant lines tapped into the radiator lines. On the 2007–up 5.4 Shelby GT500, a van-style relocation adapter was made to mount the oil filter down the side of the block. This part was cast with 7R3V-6884-BB and may also carry PN 9R3v-6884-AA1.

Steering System

The Mustang II conversion with rack-and-pinion steering system provides far more precise and controlled steering. The old worm and sector steering had a lot of issues with play and road feel.

The driver-side exhaust manifold or header frequently contacts the worm gear steering gearbox that’s positioned on the side of the frame rail. The header often heats up the gear and causes premature failure or early wear. The rack-and-pinion conversion systems generally eliminate this conflict as there is usually a solid rod going from the steering rack to the steering column. Rack-and-pinion systems mounted behind the oil pan can cause interference with some traditional header designs (see Chapter 9), so take this into account when selecting a conversion rack for your car.

Several manufacturers now sell a conversion rack that replaces the original-style rear-steer system with a modern rack. Total Control Products makes a rack-and-pinion system for early Mustangs, Torinos, Falcons, and Fairlanes. In addition, Randall’s Rack has designed a system to fit early Mustangs. Both of these companies took time to engineer out the bump steer issues, rather than just make a part that fits. These conversions usually use a modern pump, which is already pressure ready to run the rack-and-pinion system, so the conversion is convenient and you don’t have to worry about the operating pressure. Some systems adapt the old-style pumps, but they are not designed to operate a rack steering gear.