Jim Smart
January 9, 2017

Fox-body Mustangs are experiencing a resurgence of enthusiasm in 2017. You can buy fuel-injected 1986-1993 classic 5.0L Fox-body Mustangs all day for under $1,000 in fair condition, leaving you a wad of cash to build a terrific high-performance ride. Classic Fox Mustangs are hot, plentiful, and cheap offering great bang for the buck fun. They remain lightweight simple machines nearly anyone can afford and build.

The beauty of the 5.0L pushrod small-block V-8 engine is its wonderful simplicity. No overhead cams or “standing room only” Modular sizing to sweat out. The small-block Ford V-8, which was introduced in 1962, enjoyed a lengthy production life spanning four decades making it one of Ford’s most popular performance engines ever.

5.0L Power Recipe

In this case, our buddy Gil Roiz wanted to know what he had under the hood of his 1989 Mustang GT convertible. On a chassis dyno, Gil’s latest acquisition with its worn out 5.0L engine managed 220 horsepower and 230 lb-ft of torque at the drive wheels from a replacement engine that had been installed in the car. This means Ford’s venerable 5.0L engine makes on the order of 300 horsepower and 300 pounds torque at the crank from the factory. When you consider power losses through the driveline courting 50-70 horsepower, 230 horsepower and 300 torque are good numbers from a tired mill.

Gil wanted more from his $500 Mustang droptop. He began putting together a plan to make 400+ horsepower and 400 lb-ft of torque at the crank. He wanted a streetable Mustang with good road manners he could drive anywhere. He looked to Air Flow Research (AFR) for cylinder heads, Crane Cams for the cam and valvetrain, Holley for induction, MSD for ignition, BBK Performance for innovative power adders, Fel-Pro for great gasket technology, ARP for fasteners, Summit Racing Equipment and Ford Performance Parts for an assortment of speed components; Eagle for an ESP steel crank, H-beam rods, and Mahle coated and forged pistons; and Centerforce for the Dual-Friction clutch and flywheel.

When Gil bought his Mustang, the seller included the car’s original untouched 5.0L with a spun rod bearing. It was a standard bore block and the heads had never been off. We took this original matching number 5.0L engine and hauled it to JGM Performance Engineering in Valencia, California.

We have a great formula for streetable/weekend racing performance, a nice balance of brute power on demand and smooth street performance for the commute. Gil wanted a civilized idle along with stunning amounts of power when the throttle was pinned. We looked to AFR for guidance on how to build an optimum street/strip 5.0L engine.

AFR asked us about what we wanted in terms of horsepower, torque, and overall performance. AFR then went to work in its research and development lab fine-tuning a pair of custom AFR 185 Renegade cylinder heads for our blueprinted 5.0L short-block. To get the compression desired, 10.67:1, AFR milled the heads to achieve 48cc combustion chambers. It then massaged ports and chambers and did a nice custom valve job with 2.02/1.60-inch intake and exhaust valves. The 10.67:1 compression ratio was achieved with .041-inch thick Fel-Pro Perma-Torque 1135 head gaskets.

AFR enabled us to conceive what is a 400-500 horse small-block from a 4.030-inch bore and 3.000-inch stroke (306ci). We investigated what Crane had available for this application and came up with a nice grind in an off-the-shelf hydraulic roller with 110-degree lobe centers — .584/.550-inch intake/exhaust, duration at .050-inch 222/226. For greater valve lift, Crane suggested its Gold 1.7:1 ratio roller rockers along with single-piece .080-inch wall thick hardened pushrods. We have a slightly lumpy idle, which is tolerable at the traffic light, and gangbuster power when the light turns green.

When you’re planning 400-500 horsepower, you want an engine that’s going to stay together at 6,000-6,500 rpm. We contacted Eagle Specialty Products to see what they recommended. Eagle suggested an ESP Armor 4340 steel crank with a 3.000-inch stroke, H-beam rods, and coated Mahle forged flat-top pistons with valve reliefs large enough to clear our 2.02-inch intake valves. ESP Armor Plate ESP Armor is a revolutionary new surface finishing process developed exclusively by Eagle Specialty Products. Eagle tells us this is not a coating. The material you see is the same material on the surface you have always seen; just micro finished to perfection.

Performance Recipe

Stock 1989 E7AE 5.0L Roller Block, 4.030-inch bores
Eagle Forged Steel 3.000-inch Stroke Crank with ESP Armor
Eagle Forged H-Beam Connecting Rods
Eagle/Mahle Forged 4.030-inch Pistons
AFR 185 Renegade Cylinder Heads, Custom Port/Bowl Work, Milled to 48cc with 2.02/1.60-inch intake/exhaust valves,
Intake Port Volume 185cc
Exhaust Port Volume 70cc
Intake Port Dimensions: 2.045-inch x 1.205-inch x 3/8 Radius
Exhaust Port Dimensions: 1.355-inch x 1.360-inch


Crane Cams Hydraulic Roller, 44HR00217
Grind Number: HR-222/344-2S – 10 4A
Intake: .344-inch lobe lift, Exhaust .324.1-inch lobe lift
Intake: .584-inch valve lift, Exhaust: .550-inch valve lift
Advertised Duration @ .004-inch: Intake 283, Exhaust 288
Duration @ .050-inch: Intake 222, Exhaust: 226
Spring Pressure: PN 96870, Triple,
154 lbs Closed @ 1.850-inches
383 lbs Open @ 1.330-inches


Holley SysteMAX Induction PN 300-72S
Ford Performance 24-pound Injectors
BBK 75mm Throttle-Body PN1503
BBK 75mm EGR Spacer PN1600
BBK Cold Air Kit
BBK Mass Air for 24 lb/hr Injectors
BBK Adjustable Fuel Pressure Regulator
BBK Billet Fuel Rails
BBK Long Tube 1 5/8-inch Long Tube Headers
BBK Matching 2.5-inch High Flow Short Mid X Pipe with Cats
Moroso Road Race Oil Pan/Windage Tray/Pick-Up
Speed Pro High Volume Oil Pump
Centerforce Dual Friction Clutch & Flywheel
Summit/Powermaster 130-Amp Alternator
Summit Trunk Mount Battery Kit (better weight distribution)
Mishimoto Silicone Cooling System Hoses from Summit Racing
Edelbrock Water Pump
MSD Thick Film Pro Billet Distributor
MSD 8.5mm Ignition Wires
MSD Blaster HVC Ignition Coil
MSD 6AL Ignition Box
ARP Fasteners including Head and Block Studs
Ford Racing Valve Covers
Fel-Pro Gaskets Throughout

1. We’ve opted for the 4340 3-inch stroke steel Eagle ESP Armor crank, H-Beam rods, and Mahle coated and forged flattop pistons. We‘ve left displacement at 306ci in order to keep the comparison fair with our baseline tests. ESP Armor is a revolutionary new surface finish that protects and reduces friction. It is worth every penny to get it.

2. Mahle pistons are carefully assembled taking extra care not to distort rings. Gaps are staggered at 90-degrees positions for oil and leak down control. Some builders roll the rings on. Ryan uses a ring expander to prevent distortion.

3. JGM Performance Engineering has quite the variety of perfect fit piston ring compressors, which eases the installation process and saves time. Piston and rings have been dressed with engine assembly lube, which is suggested for longevity in case the engine has to sit in storage for any length of time. It ensures protection on start-up.

4. We’ve gone with H-Series race bearings for durability. Never touch bearing journal surfaces, only the sides and ends.

5. AFR specified the Crane roller hydraulic PN44HR00217 cam and 1.7:1 ratio roller rockers to enhance valve lift. The result is crisp, prompt throttle response and a broad power curve. This 5.0L mill likes to rev where torque hands off smoothly to horsepower as rpm increases.

6. Not enough engine builders inspect and blueprint oil pumps. But, JGM Performance Engineering does. Never take for granted an oil pump is good out of the box. Check the relief valve for freedom of movement, and rotor clearances, while you have it on the bench. Then, fill the pump cavity with engine assembly lube before button up. Opt for an ARP pump drive and throw the stock shaft away.

7. Moroso also provided us with a terrific road race pan and windage tray for our 5.0L project.

8. Ryan fit checks the Moroso pan including pick-up to pan clearances before final installation. We like the one-piece Fel-Pro silicone pan gasket. Talk about a time saver and leak stopper? This gasket, coupled with the one-piece rear main seal, keeps the garage floor dry.

9. Our Crane hydraulic roller bumpstick dialed in nicely, and this is very important to check. All camshafts must be degreed during installation. You must check true top dead center (TDC). Ideally, you will check true TDC on all eight bores. Although you can’t do much about true TDC, it’s nice to know where each bore stands. It is good to know how far down in the hole or above the deck each slug is.

10. Although it adds cost to an engine build, complete and total use of ARP fasteners throughout gives you peace of mind. It becomes money well spent for durability.

It Really Is About The (AFR) Heads

AFR provided us with a terrific set of AFR 185 Renagade cylinder heads with 2.020/1.600-inch cocktail tables and generous CNC port cutting. Talk about flow? These heads really do set the standard for small-block Ford power and performance. You get the horsepower, however, you also get good low to mid-range torque.

11. Close inspection of these 48cc chambers show us what’s possible given AFR technology and midnight oil in their lab; excellent quench and minimal valve shrouding. CNC machining is so darned perfect there are no hot spots or restrictions. Cutting ridges in the intake ports and chamber keep fuel droplets in suspension for good swirl and a nice light off.

12. Right-sized intake ports measuring 2.045-inch H x 1.205-inch allow for outstanding flow. You can even work these ports even further for greater power gains.

13. Small-block Ford heads are notorious for restriction issues because the factory thumb-sized ports don’t allow for good scavenging. AFR has that handled with these exhaust ports measuring 1.355-inch x 1.360-inch.

14. Fel-Pro Permatorque cylinder head gaskets live up to their name. Torque them once and never have to torque them again. However, it is always suggested you check head bolt torque once your engine has had a good warm up and break-in. These are really nice pieces, however, if you have a limited budget, then the Fel-Pro Print-O-Seal head and intake gaskets are a suitable alternative.

15. We went with Crane valvetrain components for this build including 1.7:1 ratio roller rockers, 7/16-inch studs, and .080-inch wall thickness one-piece pushrods. There’s always the debate about how to adjust valves when you have hydraulic lifters. If you’re going racing set valve lash at zero clearance (cannot turn the pushrod), then, ¼-turn clockwise. For street use, give them ½-turn clockwise. Allow the lifter to settle, then, check rocker play. You should experience a nice chatter with these Crane roller rockers.

16. Gasket technology has made quantum leaps in recent years. These steel reinforced silicone valve cover gaskets from Fel-Pro keep oil where it belongs. Not only do they seal, they create a dam, keeping oil below the valve cover lip.

17. A good example of Gil’s craftsmanship; these are classic Ford Racing finned aluminum valve covers.

18. If you wwant to make light work of the intake manifold installation, then opt for these ARP intake studs. They allow for perfect alignment and ease of installation.

Induction Seduction

When you think of induction, it’s easy to think Holley because Holley has been around for more than 100 years. In fact Holley was one of the very first carburetor manufacturers in the world. Holley’s Systemax induction for 5.0L High Output engines is a natural extension of what these 5.0L engines can do.

The Systemax 300-72S intake manifold is a nice looking piece employing lengthy right-sized intake runners for nice breathability. It allows the 5.0L engine to haul in healthy amounts of air where it gets mixed with fuel and drawn into the AFR 185 chambers.

19. We like the Holley Systemax and BBK’s 75mm throttle-body and adjustable regulator for their ability to breathe and make both torque and horsepower. On Ray McClelland’s Full Throttle Kustomz chassis dyno, we managed to get 360 rear-wheel horsepower along with comparable torque. At the crank this engine made somewhere around 450 horsepower. Not bad when you consider this is stock displacement. We’re currently running 24 lb/hr Ford Performance injectors, but Ray suggested stepping up to 30 lb/hr injectors and a second tuning.

20. Gil Roiz installed the Moroso flexible dipstick tube from Summit Racing Equipment, which enables an accurate assessment of how much oil you have down there.

21. We've opted for the Moroso PN20506 road-race 7 1/2-quart pan with PN22930 windage tray and PN22971 braided dipstick package. This gives us bountiful amounts of oil at high rpm.

22. MSD Ignition set us up with a complete billet distributor and ignition wires, a Blaster coil, and 6AL box to keep spark timing on message. The 1986-1995 Mustang 5.0L engine employs thick-film ignition technology. Thick film has struggled with heat issues and ignition failure. MSD engineered the troubles out with a fiercely reliable ignition system. In 1994-1995, the thick film module is away from the distributor.

23. Our JGM Performance Engineering 5.0L engine has a great supporting cast consisting of MSD Ignition and a lightweight Powermaster starter provided by Summit Racing Equipment. We have a turnkey package here, which made it easy for Gil to get back into his Mustang.