Approximate Installation Time: 6-8 hours for novice.
Parts required to accompany the installation of heads (If Applicable):
• If using a GT40 style intake (Cobra, Tubular GT40,) it is highly recommended to use Ford Racing Intake Gasket Set. Item # 50265, reason being the gasket is .065” and helps port matching the intake to the heads. Always do a test fit and shine light into the intake to view the port match before doing install. Not all intakes fit perfectly and may create vacuum leaks if the wrong gasket used.
• Must use special step washers for installing GT40X heads (Heads have larger ½” bolt holes for 351 motors, stock 302 has smaller 7/16” diameter head bolts). I used Item #50146, which is Ford Racing 289/302 head bolt kit that has the required washers.
• Valve cover gasket set. I used Item # 50264 from American Muscle.
• Upper plenum gasket. (Cobra/GT40 intake style: Item # 50585 on American Muscle)
• Exhaust manifold gasket set. Item # 50257 (fits stock as well as many aftermarket headers on market.) Test fit your header to the cylinder head prior to install, the exhaust ports are much larger than stock E7TE heads and single flange headers are difficult to seal without the correct gasket. I prefer to use a good quality copper spray-a-gasket with the installation of exhaust manifold gaskets.
• Head gasket set. For this install I used American Muscle Item # 50118.
• Pedestal rocker arm shim kit (If proper rocker arm geometry/preload unable to be achieved) Item # 50310 on American Muscle.
• Longer or shorter pushrods if necessary (Depending on cam, rocker arms and lifters utilized it may be necessary to purchase pushrods of correct length. A pushrod length measurement tool is handy and inexpensive to determine size you require.)
• ARP thread sealant (Item # 18221 from American Muscle)
• Assembly lube (Item # 18222 from American Muscle) comes with the Head bolt kit #50146. .
• GT40X heads call for AGSF-32C or equivalent spark plugs. American Muscle sells TR-55 NGK V power plugs Item # 64021 (Used in this installation guide)
• Jack with pair of jack stands and wheel chocks
• Clean well lit work environment
• Power Steering puller/installer tool
• Penetrating fluid
• Torque wrenches (inch lbs and one in foot lbs)
• Breaker bar ½” drive
• Large pry bar
• Rubber mallet
• Razors and gasket scraping/cleaning materials (wire brushes etc.)
• ¼”, 3/8” and ½” ratchets
• Socket and wrench set with the following sizes: 1 1/8”, 1 1/16”, metric 8mm through 20mm, standard size 5/16” through ¾” (A large adjustable wrench can be substituted for 1 1/8” and 1 1/16” socket sizes for EGR air tub and ECT sensor/coolant crossover tubing.)
• Extension bars of 6” and 9” length in 3/8” and ½” drive
• Universal joint sockets 3/8” and ½”
• Oxygen sensor socket (If factory mid pipe the 02 sensors obstruct reaching collector nuts and is easier to remove the 02 sensors.)
• Approximately 1 gallon of coolant
• Oil and filter (For oil change after finished)
• Fuel line disconnect fittings, size ½” and 5/8”
• Serpentine belt tool (Or use ½” breaker bar etc.)
• Torx head bits: T-20 for upper plenum cover and T-45 for belt tensioner center bolt.
• OBD-I code scanner, or knowledge of how to do paperclip/needle sweep method to read any trouble codes that may occur.
• Timing light
Helpful Hint Before Starting:
If able to, the night prior to the installation, warm car up to normal operating temperature and spray penetrating oil on engine and allow to soak overnight. You particularly want to hit the lower intake manifold bolts and accessory bolts on front of engine, EGR air tube, exhaust manifold/header bolts and exhaust collector bolts. This will help in removal. The day of the installation don’t be afraid to soak it all again with penetrating oil for good measure. Power steering pump puller and installation tools are usually available for renting at local parts stores, be sure to acquire this as well as all the necessary tools and parts needed before beginning this project to avoid having to wait for parts to arrive by mail or have to drive out and hunt down last minute parts that were forgotten. Installation was done on a 1995 GT 5.0. 79-93’ models and all others will have many of the same basic steps of installing the cylinder heads, having a repair manual handy for your car is a good thing to have.
Special Notes: This guide is assuming the motor is remaining inside the vehicle. For installation of cylinder heads on an engine stand, skip ahead to step 35. This guide was written while working on a 1995 Mustang GT. Foxbody years will be slightly different in some steps.
1. Place vehicle on flat surface and apply emergency brake, chock wheels.
2. Disconnect battery.
3. Carefully relieve pressure from fuel system (Have rags handy to soak up fuel when opening Schrader valve on fuel rail).
4. Jack up car and support on jack stands. Remove the two 11/16” nuts on either side exhaust manifold collectors. An extension bar and universal joint makes the task easier. If oxygen sensors (02 sensor) are in the way, make sure you have an 02 sensor socket handy. Once both sides are free, lower vehicle back down to the ground. Take note of your lower radiator hose, if the clamp is not accessible from up top of the car, loosen it and manipulate it so you can reach it easily from above to make the job easier of draining the coolant system.
5. Using screwdriver, begin removal of air intake tubing. Loosen clamps and pull off of throttle body. Disconnect intake air temperature sensor (IAT) from air inlet tubing. If using factory airbox or a cold air intake (CAI) you can leave the airbox/CAI in place on fenderwell.
6. Carefully remove the throttle return spring being careful it does not go flying.
7. Rotate the throttle body wide open with one hand, the other use to pop out the throttle cable with the slack in the line created. Pop off cruise control cable if equipped (Photo 1)