There was a time--maybe before many of you could even drive or think about owning a Mustang, but nonetheless, there was--when you would be hard-pressed to find a performance part for the 5.0 Mustang. Turn on your time machines and come back with me to 1989. The 5.0 movement was just getting under way. Ford helped fuel the fire by offering a 5.0 LX Sport model with all the GT features but in the smoother and sleeker LX body.
Aside from a set of Flowmaster mufflers, a Hurst short-throw shifter, and a K&N direct-replacement panel filter (the standard performance upgrades of the period), there wasn't much to be found for fuel-injected 5.0 engines. Sure, there were a few things just emerging on the market, such as rearend gears, underdrive pulleys, and a few aftermarket camshafts. But the real serious parts such as heads, intakes, and superchargers--stuff we take for granted today--were a few years off. The GT-40 intake with its hand-welded inlet tubes was but a prototype in late 1990 and into 1991 before it made production. The only aftermarket aluminum cylinder head was the TFS Street Heat, now known as the Trick Flow High Port. Today it takes both hands and feet to count the number of aluminum heads on the market.
Seeing the 5.0 movement gain momentum--some have likened it to the "'57 Chevy of the '90s" in the demand for the car and the desire to modify it--Edelbrock sent its engineers to the drawing board to come up with performance pieces for the 5.0. The first items to come out of the Edelbrock shipping department were induction-oriented, the most notable being the Performer 5.0 manifold.
Many years ago (it was early 1993, if memory serves) I installed one of the first Performer 5.0 manifolds on my '90 LX for testing in our sister magazine Mustang Monthly. Everyone stood around the shop in awe as the intake was pulled out of the cardboard box.
We were witnessing something--the dawn of a new age in performance. Every person in that room had to look at the manifold and touch it with their own hands.
The Edelbrock manifold was just the beginning. By the mid '90s the 5.0 performance market was in full swing. Nitrous, blowers, stroker kits, intakes, cylinder heads, suspension, electronics--you name it, it was available for the 5.0 Mustang. We witnessed a phenomenon that may not be replicated again. The time was right, the economy was right, and the car was right.
What does this little history lesson have to do with installing an intake manifold, you ask? Plenty. If it wasn't for the Edelbrock manifold and a few other companies' products that got the ball rolling, many of us would have long ago ripped the fuel injection off our 5.0s and thrown on a carburetor and a single-plane intake in its place. Since the Performer 5.0 is where many a young 5.0 owner started in the quest for performance, so shall we.
The '89 GT you see here has already benefited from articles on installing roller rockers and a stouter ignition system. Now we'll get more serious with an intake swap, and soon, the installation of a camshaft. History does indeed repeat itself.
Better Stock Up
Replacing your intake manifold takes only a couple of hours in your driveway using standard hand tools. However, there are a few "gotchas" to be aware of so you can plan accordingly and minimize your Mustang's down time, or avoid having to drive your girlfriend's Honda Accord [Tell her to buy a Focus.--Ed.] to the parts store.
* When you purchase the manifold, you get just that--a manifold. The intake will have a gasket for the upper to lower plenum junction, and side cover in the case of the Edelbrock, but that's it. You're on your own for intake gaskets to the cylinder head, throttle body gaskets, and a thermostat-housing gasket.
* Speaking of thermostats, now is the perfect time to upgrade to a 180-degree performance model.
* Inspect the cooling-system hoses and replace them during the intake swap. You'll be messing with the heater hoses, the front coolant transfer hose, the EGR cooler hoses, and the water-pump bypass hose during the job, so check them and get new ones now, not while the car is apart.
* Fuel-line disconnect tools are required for Ford's spring-lock fittings. The tools are inexpensive, so buy the entire set for future work on fuel and A/C lines.
* Since you'll be draining the coolant for the job, why not flush the cooling system and add fresh coolant on the refill?
* Most intake-manifold gasket sets come with a new distributor O-ring. If your gasket kit doesn't have an O-ring, be sure to get one. Most of the time the O-ring is so hard from heat, it simply breaks away. This is a common oil-leak path.
* Because you have to swap fuel rails and injectors from the original manifold to the new manifold, the old injector O-rings might give you some trouble with cracking or hardening. New injector O-rings from your Ford dealer are good to have on hand during the process.
 The Edelbrock Performer 5.0...  The Edelbrock Performer 5.0 intake manifold comes with a lower plenum, an upper plenum, a plenum cover, a plenum gasket (upper to lower), a plenum cover gasket, attaching hardware (upper to lower), and a gray powdercoat finish (upper only). The long runner design will yield nice, streetable torque on a decent-breathing engine, and the upper and lower plenums are CNC port-matched to enhance performance. |  Here's what our '89 GT looked...  Here's what our '89 GT looked like before we began. At this point, a MAC cold-air kit, Crane 1.7 roller rockers, and a Ford Racing Performance Parts throttle body/EGR spacer were the only enhancements to the engine. The upper intake has been off to install the rockers, but the lower intake has never been removed from the engine. |  After disconnecting the negative...  After disconnecting the negative battery cable, begin the intake swap by disconnecting the throttle inlet tube and all the intake's sensor connectors and vacuum hoses. If you think you'll have a problem hooking everything back up later, use tape to mark where these items are connected. |