2008 Pontiac G8 Rocker, Springs, Headers & Cross-Pipe Upgrade - Blown G8 Power Enhancements, V.1

Pictured are the recently removed stock exhaust manifold and the 1 7/8-inch long-tube header from American Racing Headers. Made in the USA with high-quality 304 stainless steel tubing, and complete with its race-inspired merge collector, we're expecting some serious power gains out of these babies!

Now that the exhaust was totally removed, the cylinder head bolts were yanked, as well as the heads...

...Here, George uses a valvespring clamp in order to compress the spring, facilitating easy removal of the locks.

Pictured is the stock spring on the left vs. the SLP premium-grade Beehive valvespring (PN 53003) on the right. These particular SLP units are good for up to 0.600-inch lift and fit the LS1, LS6, and LS2 utilizing the stock spring cups, locks, and retainers. It is important to measure that the installed height is 1.800-inch, anything shorter may incur coil bind...

...Once all of the springs are properly installed, the cylinder heads are reinstalled on the 6.0L and torqued to spec. The long-tube American Racing Headers were then slid into place (beyond our second teardown) and properly fastened without a hassle.

The remainder of the exhaust system was installed including the S/S cross-pipe containing 200-cell metallic substrate catalytic converters. The only remaining stock exhaust components are the mufflers, which was a matter of the car owner's preference to reduce noise and keep with the docile stock appearing/sounding theme...

...We'd also like to note that the ARH system fit flawlessly, quite possibly out-doing the stock fit. And if it performs as well as its above-average aesthetics, then we've found a winner.

Now that the exhaust is buttoned up, focus shifted back to the top-half of the engine. Pictured is the stock 1.7-ratio rocker on the left and the SLP 1.85-ratio shaft mounted aluminum unit on the right. Notice the roller tip incorporated within the SLP unit along with the beefing up of critical areas...

...The SLP rockers increase valve lift by 10% and according to the manufacturer, net gains of 12-rwhp and 10 lb-ft on a stock L92/L76 or LS3. Can't wait to see what they net on this blown G8.

ere are the rockers installed and ready to go. Being that the design is based off of the stock rocker arm, these units are easy to install and require no modifications to the valve covers. All instructions are included along with new pedestals and rocker arm bolts...

...To save time, we'll skip over reinstallation of the valve covers, coil assemblies, throttle body, intake manifold, and required ProCharger essentials. As cheap insurance we also invested in a set of SLP stock-length chrome-moly pushrods that retail for $130.

Once the G8 roared back to life, Tune Time owner,...

...Matt Hauffe strapped it to the Mustang Chassis Dyno for some testing, but not before entering into the vehicle's PCM and disabling the DOD/AFM system, which is no longer needed (due to lifter change). And the final results via the Tune Time Mustang Dyno are ...

Stay tuned to Blown G8 Power Enhancements V.2, when we beef up the fuel system and add a little methanol injection!