Tucked inside this Lunati Bootlegger box was a hefty heaping of horsepower!

By Richard Holdener

Time was when an extra dose of horsepower was the difference between being a criminal and just an outlaw. The right camshaft kept you ahead of not only the competition, but others that might be hot on your tail. Even if you aren’t running through backwoods, one step ahead of the law, who among us doesn’t want at least a little more power?

Given the popularity of the LS platform, combined with how well the engine family responds to proper cam timing upgrades, it was only a matter of time before Lunati stepped up in a big way to offer Bootlegger LS cams. After the success of their Voodoo line, the Bootlegger series was the next evolutionary step up the performance ladder. If this test is any indication, the cams delivered in the old-school, wooden box offer seriously modern performance.

Given our experience with other cam companies and profiles, we have come to expect big things from a cam swap on an LS, even one that started as a simple truck motor. To test the Bootlegger cam (and associated performance components), we snatched up a used 5.3L from our favorite LKQ Pic-a-Part wrecking yard. The used LM7 was the perfect test mule, having served faithfully for nearly 200,000 miles. Despite the mileage, the motor was sound as a pound, and ready to rock once installed on the dyno.

Rather than run the test mule in stock trim, we decided to upgrade the little LM with a revised induction system. After the upgrades, we would then run a back-to-back cam test on the modified motor to demonstrate the merits of the Bootlegger cam profile. Understand that the gains offered by the cam swap are a function of the power output of the original test motor, meaning a larger, modified motor will show greater gains than something like a bone-stock 4.8L.

To prepare for the cam test, the 5.3L was first disassembled down to the short block. After removal of the stock 706 heads and truck intake, they were replaced by a set of TFS Gen X 205 heads and FAST LSXRT manifold. The TFS Gen X 205 heads were designed for small-bore, LS applications, making them perfect for 4.8-5.7L applications, including our 3.78-inch bore 5.3L. The TFS heads offered enough flow to support more than 550 hp, but we would be getting nowhere near that number with this mild application. The TFS heads were fed by a FAST LSXRT intake and matching 102mm Big Mouth throttle body. The LSXRT is advertised as a truck intake, but it works well on any LS application with sufficient hood clearance. The FASTintake was run with a set of FAST injectors and matching billet fuel rails. Completing the system was a FAST XFI management system, 1 7/8-inch Hooker headers, and Lucas 5W-30 synthetic oil. All testing was performed with a Meziere electric water pump (no accessories), open throttle body (no air intake), and no mufflers (simple collector extensions).

The first step in the cam test was, naturally, to run the modified 5.3L with the stock LM7 cam. Run with the stock 5.3L truck cam, the modified LM7 produced peak numbers of 391 hp at 5,700 rpm and 399 lb-ft of torque at 4,800 rpm. We knew the stock cam was holding back the power output of the combination, but had no idea just how much until we performed the cam swap. The cam supplied by Lunati was a healthy candidate for our 5.3L, offering .595 lift, a 224/240-degree duration split, and 111-degree lsa. In addition to the cam, Lunati also offered new roller lifters, a set of aluminum roller rockers, and a double-roller timing chain. In anticipation of the new Bootlegger cam, we also installed a set of Lunati beehive springs, hardened pushrods, and a bottle of break-in concentrate.

Modified 5.3L Cam test-Stock vs Lunati Bootlegger
The graph clearly shows that the Lunati Bootlegger cam offered serious power gains. Run with the stock cam, the modified 5.3L produced 391 hp and 399 lb-ft of torque. After installation of the Bootlegger cam, the peak numbers jumped to 482 hp and 426 lb-ft of torque. The cam alone increased the power output by more than 90 hp and 27 lb-ft of torque. The gains exceeded 100 hp out at 6,400 rpm, and the Lunati cam continued to pull all the way out to 7,000 rpm.

After installation of the Bootleggger cam, the power output of our modified 5.3L jumped to 482 hp at 6,800 rpm and 426 lb-ft at 4,900 rpm. That means the Bootlegger cam increased the power of the 5.3L by more than 90 hp. XXXcelent power gains indeed and enough to make the difference between a criminal and an outlaw!

Sources: FAST, fuelairspark.com; Holley/Hooker/Weiand, holley.com; Lucas Oil, Lucasoil.com; Lunati, Lunatipower.com