Value is subjective, and when it comes to personalizing or modifying your truck, it often seems that performance comes up short of expectations, especially when the out-of-wallet investment has been considered. In other words, the value isn't always great.

Of course, each person's experience is different. We recently spent a couple of days in the garage with an '06 Chevy Silverado and a bed full of performance and appearance parts from SLP Performance Parts Inc., which brightened our outlook on the return of investment through bolt-on upgrades.

The appearance items included SLP's "RSX" items, such as stainless grille inserts, body side stripes, and a non-functional hoodscoop. They were monkey-simple to install and any enthusiast could perform the upgrades in an hour or two-after having the scoop professionally painted. All of the parts are available individually, too. And to round-out the updated look, we also found a set of take-off factory 20-inch wheels and tires, which really enhanced the look of the truck for comparatively little cash.

On the performance end of the project, we installed one of SLP's PerformancePac kits, which upped the at-engine output of the Silverado's 5.3-liter engine to 350 hp; the factory rating was 295. We also received chassis dyno numbers on the conversion, which confirmed the claims: stock output of the 5.3L truck was 242 hp and 274 lb-ft of torque at the wheels; with the PerformancePac, rear-wheel output jumped to 291 hp and 322 lb-ft.

The PerformancePac, one of several different SLP packages for various GM truck engines, included: a cold-air induction box, gorgeous stainless and ceramic-coated headers, a after-cat exhaust system with polished tips, a DiabloSport II handheld tuner with an SLP-specific custom tune, and most importantly, a set of 1.85-ratio replacement rocker arms. The higher-ratio rockers effectively gave the engine the equivalent of more camshaft lift with legal emissions, too. In fact, all of the parts in SLP's PerformancePac kits carry the all-important California Air Resources Board (CARB) EO number.