ocker arms are one of those component topics that don’t get their share of attention. For performance engines, there are some important considerations that might alter your perception of these simple devices. For this story we will focus on the small- and big-block Chevys as well as the LS powerplants. Over the years, the design of a basic rocker arm has evolved and, as you will see, for the better.

From the beginning in 1955, the small-block Chevy fell under scrutiny for its unusual stud-mounted stamped steel rocker arms. Until that point, most production engines with overhead valves relied on shaft-mounted rockers. An individual rocker mounted on a stud was less expensive to build and eventually spawned an industry.

1. This is the rear of the stock Camaro, and it’s about to undergo a major transformation.

e have been following this unique 1968 Camaro build at Roadster Shop for a couple of installments. This time we’ll look at the tasteful modifications made to the rear of the car.

The first step was filling the gas cap opening and the hole for the decklid key. All the joints on the rear corners were finish-welded and smoothed at this time.

The fit of the rear bumper was tightened up against the body, and the holes for the original bumper bolts were filled. All the bumper surfaces were metalfinished at this stage.

There will be twin exhaust pipes exiting in the center of the car. The original license plate mount was removed and a new panel was formed with the cutout for the exhaust tips. The license plate was moved up a few inches, and the center of the rear bumper was removed. Portions of the removed bumper section were worked into a bullet shape, which will cap the cut ends of the bumper.

f you have not been studying the progression of alternator technologies, you may not realize that since 2010 GM has been using PWM-controlled alternators in many vehicles, and all 2014-up Gen V LT-series engines use them. This is not much of an issue if you have a factory-stock vehicle, but for LT swaps and modified factory Gen V–powered Chevys it can become a big issue.

This all started back in the mid 1990s when GM started using ECM-controlled alternators. The idea was to reduce engine load when it was not needed to increase fuel economy. By the time we got LS engines they were all ECM controlled. This is why you use a separate trigger wire and resistor on the alternator for Gen III LS swaps. Gen IV/V alternators are different. These are PWM-controlled, they receive a signal from the ECM that not only turns on the charging but also changes the voltage at which the alternator outputs from 11 to 15.5 V.

The issues are twofold. First, the factory components are designed to work with the varying voltages, but many aftermarket components operate best at 14.4 V; anything lower causes problems. For example, fuel pumps may run slower, delivering lower fuel pressures, cooling fans may spin slower, electronics such as controllers and car audio may show odd behaviors.

at Musi made his bones building top-flight engines for drag racing. Drivers running Musi engines have won championships in numerous classes, but the engine builder is most famous for his nitrous-huffing big-blocks. 

Musi has been in business since 1970, and almost exclusively building ultra-competitive competition engines the whole time. But that’s changed recently. Thanks to a partnership with Edelbrock you can now purchase a genuine Pat Musi Racing Engines big-block Chevrolet, perfect for hot street performance or even drag racing. Maybe best of all, because of the partnership, the engines can be had for a real steal. There are currently three versions, and as this went to press the lowest cost carbureted engine could be had for less than $19,000, while the most expensive EFI big-block comes in for just about $3,000 more.