The crazy times we live in as gearheads. Wasn’t that long ago, a performance car leaving the factory with 400-plus horsepower was equivalent to owning your own street-legal racecar. Today, having 400 ponies to destroy your tires with is about as special as going to Walmart. But the great thing about the LS platform, and in particular the LS3 and its factory horsepower rating of 426, is that stock is just the starting point. The aftermarket is rife with parts that can have an “average” LS3 making enough power to destroy any car you’re likely to encounter on the street.
For the fifth-gen Camaro SS owner, Summit Racing has a Trick Flow Specialities top-end kit (TFS-K326-580-520) and Trick Flow by Stainless Works headers and cats that’ll have your LS3-powered Bow Tie pumping out LS7-like power (or better) in virtually no time. The kits consist of heads, cam, long-tube headers, and high-flow catalytic converters.
For our test, we headed over to Antivenom Performance in Seffner, Florida, with a bone-stock, six-speed-equipped ’13 SS that would give us the perfect platform to test the Trick Flow kit. The Antivenom crew had the install done in a day and the car back on the dyno to measure the results. We were somewhat shocked by the baseline test, as most LS3s put at least 370 hp to the wheels. The 348 rwhp baseline from this one represents the low end of the spectrum, one lower than we’ve ever seen before. Here’s what we got.

1. Our subject car was a low-mileage, six-speed, manual-equipped ’13 Camaro SS. On the Anitvenom Dynojet chassis dyno, it made 348 hp and 351 lb-ft torque. This is the lowest output of any stock LS3-powered SS we’ve ever seen.

2. The first step (after letting the engine cool) was unbolting and removing the factory iron exhaust manifolds.

3. After removing the factory airbox assembly and disconnecting the fuel lines, the intake manifold is unbolted and removed.

4. With the intake out of the way, the ignition coil assemblies are unplugged and removed, the valve covers unbolted, and then the factory rocker arm assemblies are taken off the stock heads. We’ll be reusing the factory rockers (with a trunnion upgrade) after installing our new heads.

5. Our ’13 Camaro is equipped with electric power steering, so just this idler pulley bracket needs to be removed. For earlier cars with hydraulic assist power steering, the pump will be unbolted and set aside.

6. With everything clear of the heads, they’re unbolted and removed. From the factory, all LS engines come with torque-to-yield head bolts, which can only be used once. After the heads are off, pitch those fasteners in the trash so you don’t accidentally reuse them.


7. On the right is the stock LS3 head, and on the left is our new Trick Flow Gen X 255 CNC-ported head, PN TFS-32610001-C01. They feature fully CNC-ported 255cc intake runners, CNC-profiled 69cc combustion chambers, and 2.165/1.600 valve diameters. The Trick Flow heads come fully equipped with high-performance dual valvesprings. Depending on your requirements, they can be spec’d out with two different rate valvesprings, and titanium or steel spring retainers.

8. The Trick Flow heads are taller than stock LS3 heads, with revised intake ports that have a straighter shot at the intake valve. With less bend in the intake port, the air/fuel mixture can travel at a faster velocity, allowing for more of an air/fuel charge to be sucked into the combustion chamber while the valve is open. That translates to more horsepower, especially when combined with a bigger cam and/or a power-adder.

9. One of the extra things you’ll need to install the Trick Flow top-end kit (or swap heads on any ’08-up LS-series engine) is a pair of these coolant plugs, GM PN 12602540, and a pair of the necessary bolts to install them, PN 11588714.

10. Another part that’s highly recommended for this install is Summit’s trunnion upgrade kit for LS rockers, PN 143002. This kit replaces the factory trunnion and uncaptured needle bearing assemblies with a full circumference trunnion and fully captured needle bearing assemblies. Under high-horsepower and extreme-duty conditions, sometimes the factory rockers will eject their needle bearings into the engine, which can potentially damage the oil pump or anything else the oil flows through. It’s a cheap upgrade that gives added durability to the valvetrain.

11. Back to the engine, with the heads off, the radiator and water pump are removed, followed by the harmonic balancer. Then the timing cover can be unbolted for the cams swap.

12. Before the cam sprocket can be removed, the factory tim-ing chain tensioner has to be pinned back to relax the chain.

13. After the sprocket is unbolted from the cam and removed, the cam retainer plate is unbolted from the block so the cam can be removed.

14. Out comes the cam. The factory LS3 cam isn’t a bad cam, but its design is on the more conservative side, with a lift of 0.551/0.525, duration of 204/211 at 0.050, and lobe-separation angle of 117. With the extra flow capability of the new Trick Flow Gen X heads, swapping to a bigger cam only makes sense to get more power out of the engine.

15. The Trick Flow cam that comes with the kit specs out at 0.625/0.625 lift, 113 lobe-separation angle, and 230/238 duration at 0.050.

16. Included with the kit is a fresh pair of factory GM MLS head gaskets, PN 12610046.

17. Now we can set the new Trick Flow heads in place. Even though they feature revised intake ports and the head itself is taller than stock, the factory intake will still bolt down with no problems.

18. Also included with the kit is a set of fresh, factory-style head bolts. The Trick Flow heads are torqued down to factory spec.

19. Because the new heads are taller, they require longer-than-stock pushrods. The kit comes with a set of one-piece, heavy-wall (0.080-inch) Trick Flow pushrods, PN TFS-21407750. They’re made of 4130 chrome-moly steel 5/16-inch in diameter and 7.750 inches in length. Stiffer than the factory pushrods, these pushrods will enhance valvetrain stability (especially at high rpm) because they have less flex. When a pushrod starts to flex under lift, that lift isn’t being transferred to the rocker arm, which means the valves aren’t opening fully.

20. With the heads in place, we can install the exhaust upgrades. With the factory manifolds gone, next up is removing the factory cat assemblies from each side.

21. The Trick Flow by Stainless Works long-tube headers feature 16-gauge stainless steel primary tubes with 3-inch collector diameter and a 3/8-inch-thick mounting flange.

22. Another part of the kit is this extension plug for the wiring that goes to the oxygen sensors. Because of the long-tube headers, the oxygen sensor mounting points are moved rearward, requiring the wiring extension.

23. The Stainless Works headers feature an extra-thick 3/8-inch flange so they won’t distort and cause an exhaust leak when tightened down.

24. Because the Trick Flow cam uses a three-bolt sprocket (instead of the factory single-bolt unit), you’ll need to have a three-bolt cam sprocket (GM PN 12586481) and a cam bolt set (ARP PN 134-1003) to reinstall the timing chain. After the sprocket’s bolted down (we used a dab of Loctite on the bolts), the chain tensioner can be released and the timing cover reinstalled.

25. With the cam in place, we can reinstall the valvetrain. First are the new Trick Flow rocker arm stands, included with the kit. The factory rocker arm stands will not work on the Trick Flow heads, so you have to use these new ones. But they will accept the factory rocker arms, along with aftermarket rockers as well.

26. Thanks to the net-lash valvetrain design of the LS series, rocker arm install is a snap. Just reinstall the rockers and tighten down their retaining bolts to factory inch-pound specs. No need to adjust and set lifter preload like on the old Gen I motors.

27. With that done, the front accessories can be bolted back in place. Then the radiator/cooling fan assembly can be reinstalled.

28. The intake manifold is reinstalled and the fuel line is hooked back up to the fuel injector rail.


29. Replacing the factory catalytic converter is this high-flow Metal Matrix 200 cell catalytic converter from Stainless Works. While still cleaning engine emissions to the stringent standards set by the EPA, they feature less flow restriction than the factory cats, along with more resistance to the increased exhaust heat generated by a performance engine.

30. With everything buttoned up, Antivenom’s Greg Lovell applies the necessary computer tuning to get the most out of the Trick Flow kit. One key area of tuning here is with the oxygen sensors. Because they were moved rearward due to the long-tube headers, they require more time to heat up to operating temp. Without tuning, the computer will read the O2s as being slow to respond and throw a check engine light.

31. With everything set, the car was strapped back down to the Dynojet. The results were a peak horsepower of 450 and peak torque of 420. That’s an increase of 102 hp and 68 lb-ft of torque. And as the chart in the body text shows, we saw big gains throughout the entire rpm range. On the street, you could feel the gains right off the line. The new heads give you a high ceiling for further mods in the future, like a power-adder, upgraded intake manifold, or nitrous.
Baseline | Trick Flow Kit | |||
HP | Torque | HP | Torque | |
3,100 | 194 | 329 | 219 | 371 |
3,200 | 201 | 329 | 230 | 377 |
3,300 | 206 | 328 | 243 | 387 |
3,400 | 216 | 334 | 256 | 396 |
3,500 | 223 | 335 | 269 | 440 |
3,600 | 231 | 337 | 282 | 411 |
3,700 | 242 | 343 | 294 | 418 |
3,800 | 251 | 347 | 304 | 420 |
3,900 | 257 | 347 | 310 | 417 |
4,000 | 262 | 344 | 315 | 414 |
4,100 | 270 | 346 | 323 | 414 |
4,200 | 274 | 342 | 322 | 403 |
4,300 | 284 | 348 | 334 | 408 |
4,400 | 290 | 346 | 347 | 414 |
4,500 | 298 | 348 | 358 | 418 |
4,600 | 306 | 350 | 363 | 414 |
4,700 | 315 | 352 | 371 | 415 |
4,800 | 322 | 352 | 377 | 413 |
4,900 | 325 | 348 | 386 | 413 |
5,000 | 334 | 351 | 396 | 416 |
5,100 | 340 | 351 | 405 | 417 |
5,200 | 333 | 336 | 414 | 419 |
5,300 | 328 | 325 | 424 | 420 |
5,400 | 335 | 325 | 430 | 419 |
5,500 | 334 | 319 | 437 | 418 |
5,600 | 333 | 312 | 441 | 413 |
5,700 | 340 | 313 | N/A | N/A |
5,800 | 344 | 312 | 448 | 406 |
5,900 | 348 | 310 | 450 | 410 |