They seem simple on the outside; just some wires for conducting spark. Simple as running to the parts store, grabbing some performance wires and finished — beer time. While this will work just fine for many vehicles, you might want to take a second look if your application is any more complex than a 60-year-old pickup.

More than just a wire

The job of a spark plug wire is simple: conduct the amount of current necessary to bridge the spark plug gap and trigger adequate fuel burn. Maximizing fuel burn is the key to optimizing engine performance, but there’s more to it than just delivering the most charge.

A spark plug wire can have up to seven different layers, cluing you in that there’s more going on than meets the eye. The outer layer of the wire is made from silicone and available in many different colors. All too often, a wire set is bought on appearance alone, but the silicone layer is designed to protect the wire from abrasion, heat, moisture and corrosion. A layer of braided fiberglass is next, and it provides strength to the wire and helps secure plug ends, preventing them from coming off when you pull on the wire instead of the terminal. The next layer is insulation, usually a silicone type, which is another layer of heat defense and prevents the escape of any electrical charge that has leaked through. Wrapping the braided core is a suppression layer that can vary by brand. It is the primary insulator, keeping electrical current from leaving the core and protecting it from any outside charges.

Fire In The Hole B5

The problem

The original solution for conducting spark followed the same method we use to conduct most anything else, solid wire. This method was simple and provided low-resistance conducting, but caused some problems as electrical systems advanced. The current flow of each individual charge passing through the wire creates a magnetic field, which is switched on and off as each charge passes through. This results in an electromagnetic emission that can interfere with nearby electronic systems. The resulting radio frequency interference (RFI) was picked up by car antennas and heard through radios. In modern electrical systems, RFI can cause faulty sensor readings and interfere with solenoids and modules.

The OEM fix

The first solution for reducing RFI was the incorporation of a resistor on the wire end, reducing current flow and RFI. The logical next step was to turn the spark plug wire itself into a resistor by designing a completely new core.

Most OEM wires are the carbon-core type. Carbon-core wires replace the solid-wire core with a nylon or Kevlar core with embedded carbon fiber. Resistance is both the upside and downside of the carbon-core wire. It limits the current flow in the wire as a resistor, which keeps RFI down, but also limits the amount of current that reaches the spark plug. Carbon-core wires are a cost-effective solution for manufacturers, but their high resistance (over 10,000 ohms/ft. in some cases) is a limiting factor in performance applications, and carbon cores tend to be fragile and fail more often.

If you’ve upgraded your vehicle to make more power than stock, it’s recommended that you upgrade your plug wires. For a given cylinder displacement, all performance upgrades must increase cylinder pressure or rpm. With increasing cylinder pressures, you need increasing electrical current to bridge the spark plug gap and trigger complete combustion. This is the point when wire resistance is no longer your friend.

Solid core

While we’ve made solid-core wires sound like an antiquated solution, they’re still used today in many high-performance applications. The core in this type of wire is usually made from braided stainless steel or copper, which conducts current very well and has the lowest possible resistance numbers. This allows them to transfer the most electrical charge to the plug and make the most power. However, they do not suppress RFI and can’t be used with modern electronic systems. Generally, these types of wires are only used with high-performance engines using a magneto, or a points-and-condenser-type ignition.

Spiral core

The most common performance plug wire is the spiral-core type. Spiral-core wires start with a nonconductive core of nylon or Kevlar, which has an alloy wire tightly coiled around it. A coating is then applied as another layer of RFI suppression. This form has less resistance than the carbon-core wire, but produces less RFI than the solid-core wire. Spiral-core wires usually have resistance figures under 50 ohms/ft. and will help you get the most out of an upgraded engine with any sort of modern electronics.

So what should I buy?

Armed with this info and a basic knowledge of your vehicle’s electronic systems, it should be fairly easy to decide what plug wires are right for your project. The name of the game is obviously to have the least resistance possible, but the type of electronic systems in your vehicle is really the limiting factor. Good-condition OEM wires are perfectly adequate for (mostly) stock vehicles. These wires usually have around 3,000 ohms/ft. of resistance and up. As a bare minimum, you’ll want to stay above 500 ohm/ft. with a stock vehicle. If you’ve done some performance mods, it’s time to upgrade to a spiral-core wire to deal with increased cylinder pressures. Good spiral-core wires can have less than 50 ohms/ft. of resistance. A solid-core wire can measure virtually 0 ohms/ft. and is the best performer in theory, but the lack of RFI suppression limits its use to old-fashioned ignition systems.

Article Courtesy of RCN Mag


It’s gotten easier  to drop a modern Coyote engine fitted to a

  • vintage Mustang
  • Fox body Mustang
  • Restomod project.

There is no argument that the 5.0L dual overhead cam (DOHC) from 2011 to 2017. Mustang GT known as the “Coyote” modular V-8, is great.

So with Over 435 hp without the use of a supercharger,

  • The Coyote’s cylinder head design,
  • camshafts,
  • and trick electronic valve timing control
  • each cam  controlled with independence

This means a new modular not only made good power but actually had usable torque down low. Something the Mustang was missing since its pushrod days.

The Coyote is a wide engine to fit into the engine bay. There are several schools of thought here, including all-new front suspension systems. They remove the shock towers completely, or strut-based front suspensions. It requires the very top of the shock tower to keep, but the rest can be trimmed back for engine clearance. The strut-based systems are a bolt-in. Though cutting and welding are required for trimming the shock towers. The complete front suspension conversions need a fair amount of welding and chassis prep. If your front frame rails are in rust. Or you have other structural issues a full front subframe conversion might be an option for you. Or a complete perimeter frame conversion.

Once you have your Coyote 5.0L in place and the last few issues to actually getting it wired up to run. You’ll need to figure out cooling system routing and plumbing,

engine inlet routing,

and if you are going to add or adapt to your power steering, power brakes, and A/C, and if so, how to do that.

on the last, you have the transmission decision. The Coyote you can fit with many manual and automatic transmission options. Most are a direct bolt in with the proper installation kit. Or adapter from several performance transmission resources.  which we’ll go over in the captions. So fear not! A Coyote 5.0L swap is becoming as popular an engine swap as ever. It gets easier by the day as new products aimed at helping the swap become a reality in your driveway hit the market.

Coyote with Power Steering Only

First thing’s first, you need the Coyote 5.0L engine.

Coyote Crate Engine Supercharger

If you’re looking for a little more go-power, A Supercharged Coyote 5.0L crate engine is available. We have a master warehouse of Edelbrock.  Go directly to this link for the 700 HP Coyote Street Beast


For transmission, you’ll first need to decide if you want to go manual or automatic.

The Tremec TKO-series transmission is available. These are with carbon-fiber rings to allow the higher rpm shifting which the Coyote is capable of. A low-profile top plate conversion also allows easy installation of the TKO. All this without modifying the transmission tunnel. This Coyote kit includes cross member, bell housing, clutch, fluid, fasteners, and more. More Details on the 5 Speed Kit Here Shown here is the Tremec Magnum six-speed kit. The late-model GT500 Mustang six-speed in an early Mustang means.

  • having to cut the top of the transmission tunnel,
  • change out or remove the floor support,
  • and more to get the correct driveline angle.

Most go with the 5 speed for an easier swap, plus the 6 speed does rarely get utilized.

4R70W Coyote Automatic

When it comes to automatic transmissions. Yes, the venerable C4 three-speed automatic will bolt up to your Coyote with bolt-on bell housing. But the 4 speed 4R70W is more ideal everything you need to get it behind your Coyote. It includes 

  • Smart Shift electronics,
  • manual lever sensor,
  • block plate, flexplate,
  • converter,
  • and attaching bolts.

Fitting the more modern overdrive automatics into a vintage Mustang is nothing new.

The Coyote is a drive-by-wire modular engine,  the AOD its a throttle valve (TV) shift control cable. They are not suitable for this application. A constant pressure valve body, which does not need the TV cable operation. It would rectify this issue, but you’re better off stepping up to the 4R70W.

  • With the 4R70W, Ford builds one tough overdrive automatic. Learning from the AOD’s weaknesses and improving on its strengths. The 4R70W handles 700 lb-ft of torque in stock build. Configuration and features a wide-ratio gear set (the 70 and W in the name in accordance. Add an aftermarket controller, you can adjust shift points,
  • shift feel,
  • converter lockup,
  • and more by turning a knob.

No more dropping a valve body a dozen times tweaking springs and hoping you got it rightYou can purchase the entire  4R70W conversion kit here.  It’s becoming the “go to” automatic overdrive swap choice even behind traditional pushrod engines.

The Ford 6R80 six-speed automatic found behind the Coyote in 2011-2017. Mustang is an option, albeit one that will need some floor pan surgery and a way to control it. The floor pan modification is nothing a good fabricator. It can’t make once the driveline angle is set. But know that the taller or wider transmission tunnel might make fitting a stock console. Or even stock carpeting/seats an issue. The biggest problem with the 6R80 is controlling it. There is currently a plug-and-play standalone controller for the 20011-2014 coyote.


As mentioned earlier, wiring the Coyote is a breeze if you use the Control Pack kit. It includes;

  • The body harness,
  • Inlet ducting
  • And air box,
  • Drive-by-wire throttle pedal,
  • Oxygen sensors,
  • And fuse box.

Once connecting, the harness to the crate engine and the pedal. You will have about six wire leads to connect to power the engine.


If you look back at our lead image to our story you’ll see the Ford Performance. The Coyote crate engine does not come packaged with any drive accessories. Ford offers an alternator kit with drive belt for the Coyote. Which includes the Boss 302 alternators, high-tension belt tensioner, and serpentine drive belt.

If you’re running manual steering and no A/C, the alternator kit is all you need. But if you’re looking to go all out with full accessories then you’ll need to investigate an aftermarket arrangement. One such setup is this Front Runner system.  The kit uses the industry standard Sanden A/C compressor and GM Type II power steering pump.  Along with custom brackets and spring-loaded belt tensioner. To offer a very compact setup on the passenger side of the engine.

5.0 Coyote Engine Swap Kit


Getting the Coyote down on the mounts for many of the IFS setups. It means swapping out the production rear sump oil pan for a front sump pan.  Canton Racing has the perfect answer with its new Coyote swap pans for vintage applications. Check with your suspension provider first. Though to see if they have a preferred pan that fits their suspension. Or if the stock pans will work with their cross member.

Long tube Coyote Headers

Some builders use the stock iron manifolds. This is all for the beginning of their exhaust fabrication with an engine swap. The stock manifolds on the Coyote, are a sort-of Tri-Y setup. Interfere with the chassis and steering. The best solution right now is a set of swap headers. With the Coyote swap headers for 1965-1973 Mustangs from Doug’s Headers.  And you designed it to fit the TCI and Heidts Pro-G IFS systems, though they may work with other suspensions.

Phantom Fuel pump kit

To feed that Coyote 5.0L’s EFI you’re going to need to completely revamp your vintage Mustang’s fuel system. The stock single feed line is not EFI capable.  It is not to mention you’ll need a return line to the tank, a high-pressure EFI pump, and more. You have a few options here, one being the Aeromotive Phantom fuel system. In a nutshell, it is a pump, mounting bracket, and sump in one unit. Simply cut a hole in your tank and drop it in. Aeromotive offers the Phantom by itself and as a kit with EFI regulator, fittings, filter, and more. Add the length of -6 AN hose you need and an adapter fitting for the fuel rail and you’re all set.

Coyote fuel return

This is the Aeromotive fuel rail adapter for the modular engine like the Coyote. Slip the adapter into the open fuel rail on your crate engine until it locks in place. The opposite end is machined with a male -6 AN fitting for a standard AN hose connection. The Coyote, being returnless fuel from the factory, only has one fuel rail connection. So the fuel line routing needs to be set up. The fuel return line comes off of the fuel pressure regulator. With one pressure line connecting to the engine.

Mustang Coyote Motor Spec


Cooling the Coyote 5.0L in your swap isn’t much difficult. You only need to understand the unique cooling hose routing of the Coyote.  Ensure you either use a Degas tank or have your radiator fill point be the highest part of the cooling system. Since the Coyote, and all modular engines, the company designed to use an electric fan. That’s what you’ll have to do as well—buying a radiator and fan combo is your best bet here. C&R Racing offers a Coyote swap radiator. The C&R-based unit bolts to existing core support holes.  They only need two small holes to get drilled in the bottom of the support. We’ve also used custom-built units from Flex-a-lite for modular. Coyote builds as well with great results.


So you’ve figured out your engine and transmission choices and now you’re ready to go, tools in hand. If you haven’t noticed actual fitting the Coyote into your Mustang. Then that is going to need some reconfiguring of the engine bay. A popular route is a new independent front suspension (IFS). It relocates the spring to the lower arm and eliminates the shock/spring towers. There are a number of companies that offer solutions.  Total Cost Involved (TCI) Engineering. The TCI Engineering system welds into the front frame rails. Then the suspension pieces bolt to the new subframe, providing ample clearance. The Roadster Shop offers its own IFS that utilizes modern Corvette spindles. A splined antisway bar, and other high-end goodies for a suspension. That not only allows Coyote fitment but can easily tackle the road course as well.

Ford 5.0 Mustang Coyote Engine


Detroit Speed’s Aluma-Frame IFS is another, very capable IFS. That person can consider as well and comes ready to fit the Coyote engine. The aluminum subframe structure bolts to the stock frame rails. Then sandwiches it after welding on the mounting plates. Detroit Speed’s instructions offer several part numbers for Coyote fitment, including,

  • Headers,
  • Oil pan, and more.  

Rod & Custom Motorsports was one of the first IFS manufacturers. They offer a Coyote-specific IFS package.  And now they offer a right-hand-drive configuration for those countries that need it.

The dual A-arm IFS setups are a popular route. Many Coyote swappers prefer a strut-based front suspension. With a strut IFS, you do have to maintain the very top of the shock tower, as it is the mounting point for the top of the strut. But the remaining shock tower you can cut back for engine fitment. As installed, you can see the Coyote clears fine with the shock tower simply trimmed back.

Coyote Motor Swap

Fatman Fabrications has an interesting offering for strut IFS builds. Its modular system uses a series of bolt on tubular supports. And stamped metal panels to completely reform the engine bay. It offers the most clearance for the wide Coyote. Bolt on engine mount adapters and firewall/core support bracing includes in it.


You are thinking all-new suspension front and rear for your Coyote build. You might want to forego the typical suspension kits. You need to upgrade a full perimeter frame. Offering like those from the Roadster Shop and Schwartz Performance. Simply trim away your stock front shock towers and frame rails. Weld a few mounting tabs to your Mustang’s unibody, and bolt it down on this performance frame package.

Throttle pedal Coyote

The Control Pack needs a drive-by-wire pedal. It will need you to mount thorough a custom-fabricated mount. This is an earlier pedal shown installed here, but it gives you an idea of what needs to complete. This fabbed bracket from steel sheet and bolts welded to it as mounting studs at the top and a nut for a bolt at the bottom.


One part of the Control Pack will be the airbox and possibly the inlet ducting. Depending upon accessory mounting an engine bay you might be able to get an aftermarket cold air kit to work. Like this JLT ( system shown here on a 2013 Coyote Mustang GT with a little fuss.  Alternatively, you can fab your own inlet tubing and add a mass air sensor mount and a filter to the end, as in the case of this Coyote install in a 1967 fastback. Several companies offer universal tubing, mass air sensor mounts, and filters. Gateway Classic Mustang offers a Coyote in a vintage Mustang cold air kit too, ready to go.


One area that can be a bit of an issue is the brake master cylinder. Due to the massive width of the Coyote 5.0L even using a manual brake master cylinder.  It’s mounted to the firewall can be an issue, especially in 1965-1966 applications. This is due to the near flat mounting surface of the 1965-1966 firewall versus the recessed mounting area found on the 1967-1970 firewall. The answer is to move the master cylinder over roughly 1 3/4 inches.

This will need widening the pedal support, adding length to the brake pedal arm pin, and moving the clutch pedal over as well. If it’s a manual trans car. You can see in these photos, how they moved the master cylinder over and modified the brake pedal and support accordingly.  For the 1967-1970 firewall, the master cylinder will bolt directly to the OE holes and should clear the cam cover. Ensure you use a master cylinder with outlets facing the inner fender and not toward the engine. Stang-Aholics uses this dual reservoir unit from ABS Power Brake in their swaps.

Fox Body Coyote Swap


Speaking of power brakes, as you can imagine, there is no way you’re getting a traditional vacuum diaphragm booster in such a tight spot. We’ve used hydraulic assist units in previous builds, aka hydroboost. But they need power steering and some additional line plumbing. Though they work great. A new, more compact option is a remote hydro-electric setup. Stang-Aholics uses this setup from ABS Power Brake that utilizes a small reservoir,

  • an electric pump,
  • and a high-pressure accumulator

to provide a true power brake pedal feel.


Most of the coolant hoses come with the harness kit.


Mechanical vs Electric Fuel Pump: How to Do It Right

Want an electric fuel pump to last forever and work right? We’re going to show you how to install it and wire it up the correct way!

Ok, let’s talk about the mechanical vs electric fuel pump. There is a lot of confusion and misunderstandings about them. There is also a lot of potential danger when people don’t do it right because they don’t know the right way to plumb them in or wire them…

So, let’s break it down:

When do you need an electric fuel pump?

Is an electric fuel pump reliable?

How do you keep an electric fuel pump safe?

How should you wire an electric fuel pump?

-When do you need an electric fuel pump?

Usually, a mechanical pump is preferred over an “aftermarket” electric fuel pump. They tend to be more reliable. However, sometimes that won’t work.

In my old ’47 Chevy, the engine I had swapped in had an issue. The cross member was in the way of the mechanical fuel pump. So, I ran an electrical fuel pump and had many trouble free miles.

Sometimes, people will plumb them inline with a mechanical fuel pump to add more volume and pressure. This is more for a full on drag car though…

-Is an electric fuel pump reliable?

Yes, they are. Hey, there’s about a billion cars running around right now with them. All new cars have them.

With aftermarket mechanical vs electric fuel pump though, YOU have to install them. That’s where some problems can start.

We’re here to show you the right way to do it!

So, what do I use? For a stock or performance street car, I like these Facet/Purolator mechanical vs electric fuel pump from Napa. They are quiet and work well.

A lot of people complain about some aftermarket electric vs mechanical fuel pump being junk, but usually, there is a reason they go out. It’s often the way the person installed it. There are a few things that kill them.

-Do not run them dry.

-Always run a filter before the mechanical fuel pump.

-Keep them as close to the tank as you can. Electric fuel pump pushes fuel much better than they can pull it.

-Mount them away from heat sources such as exhaust.

-Electrical Fuel pump power to them is everything. You must have the correct wire size to it. A relay is preferred. You may be getting the proper voltage to it, but not enough amps. Remember, the longer the run the more the power will drop.

-Also, the grounding of it is critical. Many people will scrape the area where they mount it or even add a ground wire. However, they forget that they don’t have a good ground from the body to the frame or to the engine. This will kill pumps real quick.

Tip: Screw into metal to the ground, not through it. “Star” washers are your friends…

Preferably, run a ground wire to the front. Many professional auto electricians will run ground wires from a unit to a common grounding point in an older car, just like in a fiberglass car. That way, there is no question if your ground is good, and it’s just 1 extra wire…

Once, a buddy and I were going to a show in his ’26 Buick roadster. It was built much like a T-bucket and it had an electric fuel pump. It was wired incorrectly and grounded by screwing into the frame by the electric vs mechanical fuel pump. We were about 50 miles out, and the pump quit…


What happened was the older metal of the frame simply wasn’t carrying the current well enough. The mechanical fuel pump overheated and shut down.

Fortunately, he had some extra wire and we screwed one end to the ground wire at the back and ran it to the front where we attached it to the negative side of the battery.

The pump started back up after it cooled down and we were trouble-free all the way there and back. When we got home he wired it in neatly and never had a problem after that…

-How do you keep an electric fuel pump safe?

The electric fuel pump can be dangerous?

Yep, without some way to automatically shut them off, they can be VERY dangerous.

But they don’t have to be.

If something lets go in your engine bay like a fuel line, the engine will eventually quit. However, if you don’t have a way to automatically shut off your electric fuel pump you will keep spraying raw fuel all over your hot engine and wiring.

Also, in a crash, your pump can continue to run feeding a fire if you don’t have a way to stop it.

Note: Never mount an electric fuel pump in an enclosed area such as the trunk or interior space…

Ok, so how do I do it right?

The easiest way is to use an oil pressure switch. The switch will stop the pump whenever the oil pressure in the engine goes away. So, whenever the engine is off, the pump will turn off automatically.

Some switches just do that. But how do I get the pump to run when I’m trying to start the motor and the oil pressure’s not up yet?

You use a three prong switch like this Standard Ignition PS-64:

The switch will also let the pump run when you hit the starter because the engine doesn’t have oil pressure yet.

Electric Fuel Pump

One wire goes to the pump, one to the start circuit, and the other to the ignition circuit. So, when there is no oil pressure, the switch connects START to PUMP, and as soon as you start cranking it runs the pump. When the oil pressure comes up, the switch connects IGN to PUMP, for normal running. When oil pressure goes away (because you just hit that rock and tore the pan off the engine, for example) it again connects START to PUMP and disconnects IGN from PUMP, so the pump shuts off.

Don’t worry, it’s easy to wire…

-How should you wire an electric fuel pump?

Since you need the fuel pump back by the tank and at the same level as the fuel or lower, that usually means you’re going to have a long run of wire. So, you need to have really good wiring going back to it. Wiring that will carry enough current. Running the current through your ignition switch isn’t a good idea since it’s probably already overloaded, and will kill the voltage. That will kill the pump. However, it’s nice for convenience. That’s why a relay is really good to use.

It lets the ignition switch activate the pump while keeping the power from having to run through it. It will keep your pump alive and happy because it is getting full voltage. A good way is to mount a relay beside a power distribution block on the firewall (see Improved Power Circuit) and get the power from there.

Here is a diagram on how to wire and plumb your pump:



Our Picks

All four of these manifolds serve their purpose in the performance community. The GT manifold is probably best suited for road race and autocross cars looking for the power coming off the corners. If all-out high horsepower for drag racing is your thing, then stick with the Cobra Jet manifold. The BOSS 302 is a cost effective upgrade as a mid-level upgrade for the 2011-14 GTs and the GT350 respectively for the 2015+ GTs.


  • 1 hp at 6,900 rpm
  • 2 lb-ft at 5,400 rpm
  • Average Power: 373 hp, 376 lb-ft – 2,800-7,500 rpm

BOSS 302

  • 4 hp at 7,600 rpm
  • 4 lb-ft 5,400 rpm
  • Average Power: 376 hp, 361 lb-ft – 3,000-7,800 rpm
  • +/- to GT manifold:+19.3 hp, -30.8 lb-ft

Cobra Jet

  • 2 hp at 7,600 rpm
  • 6 lb-ft at 5,400 rpm
  • Average Power: 386 hp, 370 lb-ft – 3,000-7,800 rpm
  • +/- to GT manifold:+40.1 hp, -20.6 lb-ft


  • 8 hp 7,500 rpm
  • 6 hp 6,100 rpm
  • Average Power: 381 hp, 365 lb-ft – 3,000-7,800 rpm
  • +/- to GT manifold:+24.7 hp, -26.6 lb-ft

More OEM Goodness from Ford Performance

When we asked what’s in store for 2015+ 5.0 enthusiasts, Kershaw remarked, “We are really close to releasing our Power Upgrade kits for the 2015-2016 Mustang GT and Power Upgrade 3 that includes the GT350 manifold. This is the first time we’ve offered one of our manifolds with a CARB EO. You can now rev over 7,000 rpm and it picks up huge of the stock manifold, nearly 70 hp at 7,500 rpm!  However, it loses some mid-range and is pricy. The Power Upgrade 2 uses the GT350 throttle body and CAI picks up 21 hp peak, over 40 lb-ft at 1,500 rpm and will be a very reasonably priced.”