Whenever you install a new camshaft into an LS engine, you will need to upgrade the rest of the valvetrain as well to match the new powerband that will typically be higher than before. Since the TFS heads already come with high-quality springs and retainers, we concentrated our efforts on a set of high-quality roller rockers and pushrods. For the rocker arms, we went with a set of trick Harland Sharp 1.7 ratio arms (PN SLS17, $399) in their signature gold-anodized finish. As many LS racers know, the stock rockers have proven to work very well in competition, but for the utmost in reliability and valvetrain stability, going to the semi-shaft design of the Harland Sharp units really locks things down considering that the factory 8mm bolts are all that are used to secure everything to the head. To finish the installation, we then went with a set of 7.5-inch TFS hardened pushrods. The original factory roller lifters and lifter retainers were re-used as they've proven to handle plenty of RPM without any problems.
Breathing Apparatuses
As LS engines go, the LS2 intake manifold is one of the least-flowing designs out there. Being on par with an LS1 intake in power potential, this left us wondering just how straddled our new engine combination would be with a rather "sucky" intake. So, a step up to a higher-flowing intake manifold was planned, but we had to examine our options first. The few intakes on the market fall into two main categories-those that are cast in aluminum and those that are molded from composite material. While the cast aluminum units on the market certainly have a durability advantage and can be ported safely for boosted or nitrous-injected applications, it's their price that makes them so attractive. They are priced quite reasonably but the weight penalty can be as much as 15 pounds, placed right over the nose of your ride.
Since we prioritized lighter weight and knew that our engine would live a simple naturally aspirated life, we went with the composite LSX 90mm intake manifold from FAST (which has been recently superseded by a 92mm version, which was unavailable at the time of print). Because all LS2s already have a 90mm throttle body from the factory, we didn't have to fork over as many greenbacks as our F-body friends would in order to have a complete 90/90 FAST setup (the FAST 90mm throttle body retails for almost $450 alone.) Another added expense was the FAST LS2 fuel rail installation kit (PN 54026, $76 from Summit Racing), which comes with fuel injector adapters and other miscellaneous hardware. In addition, keep in mind that the FAST intake manifold has its MAP sensor mount located at the rear so on an LS2 car (like ours) remember to pick up a MAP sensor relocation wiring kit. In total, adding the FAST LSX intake to your LS2 will cost you about $950 even if you re-use your factory DBW (Drive By Wire) throttle body.
Although the LSX intake is a proven performer and is a nice luxury, it is not entirely necessary for a street/strip machine, but we did it for the sake of matching our engine combo. If you are a nitrous user and abuser and don't mind the extra weight, going with one of the aluminum intake manifolds may be a great choice and can save you enough dough to use towards a good 150-horsepower nitrous system.
 Headers unbolted and rocker...  Headers unbolted and rocker arms removed, it was time to tackle the 10 primary head bolts and the five upper perimeter bolts. We love how easy it is to work on LS motors! |  With a drain pan underneath...  With a drain pan underneath to catch the coolant, Nick lifts the 243-casting cylinder head off the short-block and lays it aside. |  Side by side, the TFS GenX...  Side by side, the TFS GenX 225cc head (right) has noticeably larger exhaust ports. Even more impressive is how, in fully-assembled form, this head comes with titanium retainers and heavy-duty valvesprings that can handle .600 lift. |
 The combustion chamber of...  The combustion chamber of the TFS GenX head has more of a heart-shaped design to help unshroud the large 2.055/1.575 valves for optimum flow at all points of lift. Being that they are CNC-finished, these 65cc chambers also have less potential for detonation to occur and allow tuners to put in more timing for increased torque at low- to mid-range engine speeds. |  With the coolant pump unbolted...  With the coolant pump unbolted from the front face of the engine, the crankshaft pulley is then removed and the timing cover is undone. Thankfully, GM blessed our engines with reusable gaskets here, so just keep them clean and set the aside for installation later. |  The timing chain in our low-mileage...  The timing chain in our low-mileage GTO still looked like new, so we decided to reuse it. Note the raised groove that is unique to the camshaft sprocket for later LS engines. This works with the camshaft position sensor that is on the timing chain cover to let the PCM know where the cam is phased in relation to the crankshaft. To remove the sprocket, simply undo the three cam bolts with a 10mm socket. |