The best thing about the 5.0L Ford is how well it responds to after market modifications. Can the same be said of the small-bore Chevy?

If missed part 1 of our 5.0 Fistfight, we pitted these two 5.0-liter heros of yesteryear against one another in stock trim. The 5.0L H.O. Ford, with its 4.0-inch bore and 3.0-inch stroke was sent into battle with the LB9 5.0L TPI Chevy. The Chevy offered 3 extra inches of displacement (despite the identical 5.0L designation) and a bore and stroke of 3.736 inches by 3.48-inches. Despite a sizable difference in bore and stroke, the two engines produced very similar power numbers. In fact, the difference can be attributed more to the mileage and overall condition of the motors than the actual components. The high-mileage 5.0L Ford was at somewhat of a disadvantage compared to the factory-fresh 305, which had been pulled from the assembly line back in the early '90s for use by the Chevy race shop. The little 305 was stuck in a corner and never used, eventually finding a home here at Westech performance. Upon disassembly, the engine was found to be in pristine condition, with all the factory gaskets, sealer, and even cross hatch. It might be the lowest actual mileage TPI 305 in the country, or even the world. What we won't do for our readers!

To demonstrate how well the respective 5.0Ls responded to performance upgrades, we decided to treat the pair to new heads, cams, and intakes. We decided to keep things as even as possible by selecting a comparable trio of performance components. Obviously, there are endless combinations that can be created, but we selected parts based on a combination of power potential, drivability and visual appeal.

Enough talking, let's get the wrenches flying. First on the chopping block was the Ford. Off came the stock heads, cam, and intake to make room for products from TFS and Comp cams. The one area the 5.0L Ford has a definite advantage over the Chevy is parts availability. What? How does a Ford have more parts available than a small-block Chevy? Well, the small bore used on the 305 Chevy eliminates almost every cylinder head made for the small block. By contrast, the 4.0-inch bore on the 302 Ford allows use of every available after market Ford cylinder head, something we take full advantage of in part 3. For now, we kept things even by selecting comparable heads for both. The best head for the Chevy was from the Super 23-degree aluminum heads from TFS, so we chose the similarly-sized Twisted Wedge 170 heads from TFS for the Ford. The Twisted Wedge heads all but revolutionized the Ford market when introduced, and they remain a top condender still today. They features 170-cc intake ports, a 2.02/1.60 valve package and 61-cc chambers. Even better, they offered an additional 80 cfm of flow per runner compared to the stock E7TE iron heads.

The heads obviously needed a suitable induction, and once again TFS came to the rescue with their Track Heat upper and lower intake. Designed for street / strip use on a modified 5.0L, the Track Heat features 12.2-inch runners, which position this intake solidly between the (longer) Street Burner and (shorter) R-series intakes. We fed the intake with a 75-mm Accufab throttle body and 65-pound injectors. All testing was run using a Holley HP management system. The final modification was to upgrade the factory 5.0L cam with an Xtreme Energy grind from Comp cams. The XE274HR has been a 5.0L favorite for decades now and offers 224 / 232-degrees duration, 0.555/ 0.565-inch lift, and a 112-degree lobe separation angle.

With everything installed, we were rewarded with peak numbers of 376 hp at 6,000 rpm and 355 lb-ft of torque at 5,300 rpm, an improvement of 115 horsepower! With the Ford finalized, it was time for the Bowtie boys.

The 305 TPI Chevy was given the same treatment as the Ford, starting with a complete disassembly down to the short block. Opening up the LB9 was like stepping into the WABAC machine with Peabody and Sherman. We almost hated violating the sanctity of the time-warp, TPI engine, almost! Like the Ford, the Chevy received a Comp camshaft, XR276HR, that offered a nearly identical 224/230-degrees of duration, but the lift was a tad less, measuring 0.502 / 0.510 -inch. The Chevy cam also offered a tighter 110-degree lsa. The cam was combined with Trick Flow Super 23 175cc heads designed for the small-bore application. These heads feature 175-cc intake ports, 1.94 / 1.50-inch valves and 56-cc combustion chambers. Like the Ford heads, the Super 23 heads from TFS offered sizable flow gains over the stock TPI heads and were capable of supporting nearly 500 hp on the right application. As with the Ford, we requested valve springs suitable for our hydraulic roller cam profile.

Now that the Chevy was upgraded with new heads and a cam, it was time for an induction system. Choosing the right intake for the 305 was slightly more difficult, as we wanted to maintain the TPI style without limiting power production. Rather than choose an after market version of the long-runner TPI manifold, we decided to go with Holley's Stealth Ram. Basically a tunnel ram lower with a boxy upper intake, the Stealth Ram offered plenty of power potential while maintaining the look and feel of the TPI. The Stealth Ram was combined with a dual 58-mm throttle body from Holley, an MSD distributor (like the Ford), and run on Westech's Superflow dyno using the Holley HP management system. Once dialed in, the modified 305 produced peak numbers of 370 hp at 6,100 rpm and 349 lb-ft of torque at 4,800 rpm. Though this round went to the Ford, it is amazing how close the two were in modified form, despite the obvious difference in performance components. Ford and Chevy guys can argue all they want, but the fact is that both 5.0Ls have plenty of power potential. Check back with us next time when we replace the fuel injection with carburetion and throw the Chevy guys under the bus with a head swap on the Ford.



5.0L Ford-Stock vs Modified

Run in stock trim, the 5.0L Ford produced 261 hp and 322 lb-ft of torque. The stock cam, heads and long-runner intake limited power production beyond 5,100 rpm, but things changed for the better once we modified it with a set of TFS Twisted Wedge heads, a Comp XE274HR cam, and a Street Heat intake, the power output jumped to 376 hp and 355 lb-ft of torque. The combination bumped the power output by 115 hp and 333 lb-ft of torque, and allowed the 5.0L to pull strongly to 6,500 rpm.



5.0L Chevy-Stock vs Modified

The modifications to the TPI 305 offered similar results. Run in stock trim, it produced 267 hp at 4,700 rpm and 333 lb-ft of torque at 3,700 rpm. These numbers jumped to 370 hp at 6,100 rpm and 349 lb-ft of torque at 4,800 rpm once we installed the TFS Super 23 heads, Comp cam and Holley Stealth Ram intake.



Modified 5.0L Fistfight-Ford vs Chevy

Comparing the modified 5.0L Ford to the TPI Chevy, we see the Ford had the slight edge in power. In the big picture, a difference of 5-6 hp is hardly a clear win, but Ford guys won't let that stop them from celebrating. What is more important here is that, even after the mods, our fabulous 5.0s were still running neck and neck in terms of power production. Things will change in part there when we upgrade them once again and replace the fuel injection with carburetion.

See all 19 photos Starting with the 5.0L Ford, we stripped it down to the short block by removing the stock intake and cylinder heads. Note the double eyebrow pistons and use of Fel Pro 1011-2 head gaskets.

See all 19 photos The first thing to go was the wimpy stock 5.0L camshaft, replaced by a healthy Xtreme Energy grind from Comp Cams. The XE274HR has 224/232-degrees duration, 0.555- / 0.565-inch lift and a 112-degree lsa.

See all 19 photos The stock E7TE heads were replaced by a set of TFS Twisted Wedge 170 Ford heads, which flow 80 cfm better than the stock E7TE heads. We used ARP head bolts for both engines.

See all 19 photos The Twisted Wedge heads were topped with a matching Trick Flow Specialties Track Heat intake. The lower intake was installed with a set of 65-pound injectors and the stock 5.0L fuel rail.

See all 19 photos The Track Heat manifold's upper and lower halves combine to form 12.2-inch runners that offered exceptional torque production without limiting peak power. Style-conscience engine builders will appreciate the matching, cast-aluminum valve covers.

See all 19 photos We used Accufab's 75mm throttle body to feed the engine.

See all 19 photos Equipped with the TFS Twisted Wedge heads, upper and lower Track Heat intake and Comp XE274HR cam, the modified Ford 302 produced 376 hp at 6,000 rpm and 355 lb-ft of torque at 5,300 rpm, an improvement of 115 hp.

See all 19 photos Next up on the dyno was our TPI 305 Chevy, probably the most well-preserved example of this engine family.

See all 19 photos Like the Ford, the LB9 Chevy was stripped of its induction, heads, and camshaft, then treated to Fel Pro head gaskets. The Chevy shared the 4-eyebrow piston design with the Ford. This little TPI Chevy was in pristine condition.

See all 19 photos We replaced the stock cam with one from Comp that closely matched the one we installed in the Ford. Comp's XR276HR cam has 224/230 degrees duration, 0.502 / 0.510 lift, and a 110-degree lsa. Short of a custom cam, this was as close as we could get to the cam in the Ford.

See all 19 photos The Chevy also received a set of TFS aluminum heads to replace the stock iron heads. Trick Flow's Super 23 175 heads were designed for the 305's small-bores. They offer exceptional flow and small, 56-cc combustion chambers to maintain compression on the 305.

See all 19 photos Like the Ford, the Chevy received aluminum roller rockers to maintain accurate valve train geometry. Lunati supplied this set of 1.5:1 rollers for the Chevy.

See all 19 photos Knowing the TPI's long-runner intake manifold limited power, we replaced it with Holley's Stealth Ram, starting with the lower intake. We re-used the same 65-pound injectors run on the Ford. We used the same Holley HP EFI system as the Ford, and the settings for the 302 were almost perfect for the 305 Chevy.

See all 19 photos The upper intake was installed using the supplied hardware, and we fed the Stealth Ram with Holley's dual 58mm throttle body. Note our drive-by-(bailing) wire throttle actuation!

See all 19 photos Run on the dyno with the TFS heads, Comp cam and Holley Stealth ram, the little 305 Chevy pumped out 370 hp at 6,100 rpm and 349 lb-ft of torque at 4,800 rpm. Round two goes to the Ford, but not by much!