The Twisted Wedge Legacy

The original as-cast Twisted Wedge street head from Trick Flow Specialties had a significant impact on the 5.0L Mustang market. It was neither the first aftermarket performance head available nor the first aluminum option for the 302 and 351W. What it provided was an affordable, aluminum, direct bolt-on performance head at a time when no comparable option existed. The question now: with so many cylinder heads on the market, do the Twisted Wedge heads still deliver measurable gains?

The Test Motor: A 331 Stroker

To take full advantage of the Track Heat heads' airflow, the test required more than a stock 5.0L. A 331 stroker was selected - a late-model 5.0L block bored to 4.030, combined with a 3.25-inch stroker crank. The shorter stroke (versus the common 3.40-inch/347 configuration) reduces piston side loading.

A main stud girdle added bottom-end strength to the stroker assembly.

The rotating assembly used a SCAT 9000-series cast stroker crank, offering improved strength over factory castings at this power level and engine speed.

JE forged flat-top pistons were designed specifically for the Twisted Wedge valve orientation. ARP head studs and Fel Pro 1011-2 head gaskets completed the assembly.

Speedmaster supplied a set of 4340 forged rods (5.40-inch) for the 331 build.

The JE flat-top pistons combined with the 61cc chambers to produce a static compression ratio of 10.1:1.

Camshaft and Supporting Components

A Comp Cams Xtreme Energy XE274HR was selected - a dual-pattern cam with .555/.565 lift, 224/232-degree duration, and 112-degree LSA. This profile provides enough airflow demand to test the Track Heat heads while retaining daily-driver manners in the stroker combination. The cam required a valve spring upgrade on the stock E7TE heads; Comp supplied the 35200 spring package for adequate rate and coil-bind clearance.

The Comp XE274HR cam: .555/.565 lift, 224/232-degree duration, 112-degree LSA. Comp's XFI stroker cams offer additional top-end performance at the cost of idle vacuum and low-speed drivability.

Comp hydraulic roller lifters were installed using the factory spider assembly.

The induction system consisted of a Speedmaster Cross-Wind dual-plane intake topped with a Holley 750 HP carburetor. Exhaust was handled by Hooker 1 3/4-inch long-tube headers feeding 18-inch collector extensions. MSD supplied the billet distributor, and Milodon provided a complete Fox-chassis oiling system.

A Milodon windage tray, oil pan, and pickup ensured adequate lubrication for the 331 stroker.

The factory iron E7TE heads received an upgraded spring package for adequate coil-bind clearance and spring rate with the XE274HR cam.

The Speedmaster Cross-Wind dual-plane intake topped the 331 stroker. Stock heads ran with self-aligning, 1.6-ratio roller rockers.

A Holley 750 HP-series carburetor fed the 331.

Flow Bench Comparison

Before hitting the dyno, both head sets were tested on the airflow bench at 28 inches of pressure. The stock iron 5.0L heads managed 166 cfm from 127cc intake ports. The TFS Track Heat heads, with 170cc intake ports, flowed 251 cfm - a 51% increase. By flow-based calculation, the stock heads support approximately 330 hp; the TFS heads are capable of supporting over 500 hp on the right combination.

Dyno Results

Run on the 331 stroker, the stock E7TE heads produced 353 hp and 399 lb-ft of torque. After installing the TFS Track Heat heads, the numbers moved to 439 hp and 437 lb-ft - gains of 86 hp and 38 lb-ft at peak, with improved torque production across the full rev range.

The dyno overlay confirms the Track Heat heads added power from bottom to top, with no loss to the stock heads at any point in the rev range. Peak numbers moved from 353 hp and 399 lb-ft to 439 hp and 437 lb-ft.

With stock heads, the 331 stroker produced 353 hp at 5,300 rpm and 399 lb-ft of torque at 3,800 rpm.

The TFS Fast-As-Cast Twisted Wedge Track Heat heads installed on the 331 stroker.

The Twisted Wedge name comes from the offset valve orientation. The heads feature 61cc combustion chambers with a 2.02/1.60 valve combination.

The 170cc as-cast intake ports flowed 250+ cfm at .600 valve lift - a significant gain over the 166 cfm from production 5.0L heads.

The 66cc exhaust ports delivered 193 cfm versus 111 cfm from stock - a 74% improvement.

TFS 1.6-ratio roller rockers were used on the Track Heat heads.

With TFS heads installed, the 331 reached 439 hp at 5,900 rpm and 437 lb-ft of torque at 4,300 rpm.

Conclusion

The as-cast Twisted Wedge Track Heat heads produced an 86 hp gain over stock E7TE castings on the 331 stroker, with improvements across the entire rev range. The flow bench data and dyno results align: the Track Heat heads delivered consistent, measurable gains without requiring ported or CNC-machined castings. For a 5.0L or 5.8L Windsor stroker build, the as-cast Track Heat remains a direct, proven upgrade path.