On our test subject, a 2001 Camaro SS, these upgrades were realized during an engine build that was completed in 2007. At the time, the budget allowed for a set of PRC Stage 2.5 5.3L heads, while a TRex cam (242/248 duration, .608/.612-inch lift, 110 LSA) punished the valvetrain in daily driver duty. The PRC dual springs were more than up for the task but the factory rockers weren't. As time went on and the engine continued to see high rpm, the monster cam damaged the valveguides and reduced power. A smaller custom cam from Pete Incaudo at V Max Motorsports was installed (232/244 duration, .595/.602-inch lift, 114+4 LSA) to help combat the issue, but the damage was already done. The new cam brought the power down to a more conservative engine speed than the TRex, and picked up a lot of low-end power to make it more streetable.
According to Trick Flow, the factory rocker arms from GM were never designed to be used with a higher-lift camshaft. GM rates the OE rockers for .550-inch lift but this hasn't prevented the majority of LS-engine owners from reusing their factory rockers. The reason why it gets ignored is because it's easier and cheaper to just keep using them and appears to work at first. The potential long-term effects are worn valveguides like we have experienced, or even valvespring and stem failures.
Learning from our mistake, we decided to step up in the cylinder head department instead of simply replacing the worn valveguides. Trick Flow Specialties GenX 215cc CNC heads were chosen for their insurmountable reputation, and compatibility with our setup. The 215cc intake runner was more conventional for our forged 347-cubic-inch LS-mill, so we were confident there would be a healthy power additive. Most importantly, to prevent this from happening again in the future, we wanted to install a set of roller rockers. Crane Cams supplied us with their new Gold Race extruded aluminum roller rocker arms. They came as a kit with Crane 7.250-inch hardened pushrods and were ready to bolt in. The roller tip doesn't cause valve deflection, which is when the rocker will actually push the valve stem to one side and cause it to wear faster. This should help our valvetrain to stay alive longer in addition to being quieter than the factory rockers.