There are literally hundreds of companies that make performance parts for Chevy Silverados. In fact, all the big pickup manufacturers have come up with their own performance parts divisions to allow dealers to cash in on some of the customizing/performance dollars being spent by new- and used-truck owners.

Divisions like Mopar Performance, SVO, and TRD were created specifically to keep those parts compatible with existing engines, fitments, and quality concerns. And GM got smart, too: If people are going to modify their new trucks and SUVs anyway, why not get more involved with companies that help their buyers customize and upgrade their products? This exact partnership model works well in the conversion-van industry where GM, Ford, and Dodge each typically partner up with a single manufacturer to keep track of quality and warranty issues. That's where Regency Inc., out of Texas, comes in. With consulting help from Jon Moss, past special-projects czar for GM's "toy box," Regency offers an ordering package to all GM dealerships; Regency installs it on the vehicle and ships anywhere in the U.S.

The limited-production Silverado RST is based off the current-model rear-drive regular-cab shortbed pickup. Regency installs a cold-air induction system, replaces the spark plug wires, adds a K&N air filter, and fits ceramic-coated headers and a stunningly resonant power-flow exhaust. In addition, it fits a Ground Force suspension (lowering ride height by an inch), 20-inch aluminum wheels, and 265/50R20 Goodyear Eagle RS-A tires--and those are just the performance modifications. There are another 12 interior and exterior choices that can be made, from shifter knobs, to pedal styles, to rollpan choices, to billet inserts--all by checking the box, and all of it comes with a three-year/36,000-mile warranty.

Anyone can walk into a GM dealership and let the salesperson know they're interested in the specific outfitters code. Regency will have some ordering requirements as to what model and packages to get. A new truck is then sent directly to Regency from the plant, where it'll be built to order. Regency acts as the warehouse for the JBA headers, Ground Force suspension parts, Baer brakes, and all the other pieces that go into the setup. Right now, it's working only with regular-cab shortbeds to keep weight down, but that means the largest engine is the smallest V-8 offered by GM trucks--the 285-horsepower, 4.8-liter V-8. From our butt dynos, we'd say the headers, induction, and exhaust mods tip the package just over 300 horses.