The right induction system is critical for any 5.0L Ford.

Words and Photos by Richard Holdener

Carburetion or Injection: Defining the Question

What is the better choice for a 5.0L Ford - carburetion or injection? The question is straightforward, but the answer depends on which carbureted and EFI combinations are being compared, and what "better" means in context. Not all carburetion outperforms all injection, and the reverse holds equally true. Different configurations suit different applications.

The carbureted 302 contingent that grew up in the late '60s and early '70s - through the mid-'80s - may see things differently than the 5.0L Ford owners who built their experience around modern fuel injection. For Ford enthusiasts who predate the 5.0L, the complexity of fuel injection doesn't compare to the simplicity of a well-set-up carburetor.

Someday, we will get to use a real test motor that didn't come from the wrecking yard, but its hard to argue with the success of this little Explorer 5.0L from the LKQ Pic-a-Part. For this test, it was stripped down to the short block.

Naturally, a cam swap was needed to replace the factory 5.0L stick. The soccer-mom Explorer cam was replaced by a healthy grind from COMP Cams. The XE274HR provided a .555/.565 lift split, a 224/232-degree duration split, and 112-degree lsa.

Since a hot cam does not a motor make, we also installed a set of TFS 11R 170 cylinder heads. Thanks to revised valve angles (11 & 13 degrees) and full CNC porting, 170cc 11R heads offered some serious flow.

The Test Motor

Regardless of where the carb and EFI camps stand, this comparison puts the two configurations side by side on the same engine. The test motor was an early 5.0L Ford (302, for the carb crowd) pulled from an Explorer at a local LKQ Pic-a-Part. The short block was retained after stripping the GT-40 induction system and matching iron heads.

The stock cam was replaced with a COMP XE274HR grind - delivering a .555/.565 lift split, a 224/232-degree duration split, and a 112-degree lsa. This was about as aggressive a cam as piston-to-valve clearance would allow.

To ensure we got every last bit of the lift and duration offered by the COMP cam, TFS supplied a set of 1.6-ratio aluminum roller rockers.

The first of our induction systems to be tested was this polished Eliminator intake from Speedmaster. The dual-plane design promised a broad torque curve and plenty of peak power. For a street motor, it is hard to beat a good dual-plane design on a 302.

To ensure our ignition never missed a beat, we installed this MSD billet distributor and 6AL ignition amplifier.

Not wanting to over-carburate the little 302, we installed this Holley 650 Ultra XP carburetor.

Cylinder Heads and Valvetrain

The GT-40 heads from the Explorer were upgraded with a set of 170cc 11R heads from Trick Flow Specialties. The 170cc port volume was well-suited to the 302, and the 11R heads delivered full CNC porting across intake, exhaust, and combustion chambers. Revised valve angles of 11 and 13 degrees (intake and exhaust) complemented a 2.02/1.60 stainless steel valve package.

The 56cc combustion chambers increased static compression ratio over the 65cc GT-40 heads - a meaningful gain, given the stock 5.0L and GT-40 Cobra featured 61cc chambers. The heads were shipped with a hydraulic roller spring package rated for safe operation to 6,500 rpm. A set of Speedmaster aluminum valve covers completed the top end, covering the 1.6-ratio roller rockers and hardened pushrods.

Exhaust chores for our dyno thrash were handled by a set of 1 3/4-inch, Hooker long-tube headers designed for a Fox-chassis Mustang application. The headers were run with 18-inch collector extensions.

Test 1: Speedmaster Eliminator Dual-Plane Intake with Carburetion

The first configuration paired a polished Speedmaster Eliminator dual-plane intake with a Holley 650 Ultra XP carburetor. The dual-plane design targets a broad torque curve with strong pull beyond 6,000 rpm - well-suited to street and street/strip applications on a 302. An MSD billet distributor and 6AL ignition amplifier handled timing, while exhaust exited through Hooker 1 3/4-inch long-tube headers with 18-inch collector extensions.

Run on the dyno with the dual-plane Speedmaster Eliminator intake and Holley carb, the modified 302 Ford produced 394 hp at 6,300 rpm and 370 lb-ft of torque at 4,300 rpm.

On the dyno, the modified 302 Ford produced 394 hp at 6,300 rpm and 370 lb-ft of torque at 4,300 rpm. Torque exceeded 350 lb-ft all the way out to 5,400 rpm, and the horsepower curve held strong past 6,600 rpm.

After running the dual-plane intake, off came the Eliminator to make way for fuel injection.

Test 2: TFS Street Heat EFI

We replaced the carb combo with this Street Heat EFI lower intake from TFS. The factory fuel rail fed 60-pound Accel injectors.

With the TFS 11R heads already in place, the EFI configuration used a Trick Flow Specialties Street Heat upper and lower intake. The Street Heat featured 12.2-inch runners designed to deliver strong torque and power up to 6,000 rpm - a similar operating range to the dual-plane setup. A 75mm Accufab throttle body supplied airflow, Accel injectors handled fuel delivery, and a FAST XFI management system managed tuning.

The lower intake was combined with the long-runner, Street Heat upper intake.

To ensure plenty of airflow, we installed this 75mm Accufab throttle body.

To ensure we maximized the power potential of the EFI induction system, we dialed in the air/fuel and timing curves with this FAST XFI management system.

After dialing in the air/fuel and timing curves, the fuel-injected 5.0L produced 391 hp at 5,900 rpm and 372 lb-ft of torque at 4,200 rpm.

Run with the TFS EFI set up, the fuel-injected 5.0L Ford produced 391 hp and 372 lb-ft of torque. Though the peak numbers were very similar, the injected version offered more power from 4,700 rpm to 6,000 rpm, but fell off to the dual plane out to 6,600 rpm.

Results: Where Each Configuration Delivers

302 Ford - Speedmaster Dual Plane vs TFS Street Heat EFI. Prior to the test, the 5.0L was upgraded with a COMP cam, TFS 11R heads and 1.6-ratio roller rockers. First run with the Speedmaster Eliminator intake and Holley carb, the modified 5.0L produced 394 hp at 6,300 rpm and 370 lb-ft of torque at 4,300 rpm. The TFS Street Heat EFI upper and lower intake offered nearly identical peak numbers, checking in with 391 hp and 372 lb-ft of torque, but the curves show injection offered more power from 4,700 rpm to 6,000 rpm. The dual plane held the advantage both below 4,000 rpm and above 6,100 rpm.

Peak numbers were nearly identical: 394 hp and 370 lb-ft of torque for the carbureted Speedmaster Eliminator versus 391 hp and 372 lb-ft for the TFS EFI setup. The difference is in the curves. The injected combination delivered measurable gains from 4,700 rpm to 6,000 rpm, while the dual-plane carbureted configuration held the advantage below 4,000 rpm and above 6,100 rpm.

For a street application where mid-range power matters most, the EFI configuration carries a tangible advantage through the heart of the rpm range. For builds that prioritise top-end pull or low-rpm response, the Speedmaster Eliminator dual-plane intake paired with carburetion remains a strong choice. The answer depends on the application - and now, the data is there to support the decision.

Sources: LKQ, Lkqpickyourpart.com; ARP, Arp-bolts.com; COMP Cams, compcams.com; Holley/Hooker/Weiand, holley.com; MSD, Msdignition.com; Speedmaster, Speedmaster79.com; Trick Flow Specialties, trickflow.com