hen it comes to affordable, “bolt-on” horsepower improvements for your LS engine, the $64,000 question has always been: What’s real and what’s nothing more than snake oil? Well, believe it or not, we actually have the answer to that—and it’s rather shocking … no pun intended!

When it comes to the LS family of powerplants most don’t complain when it comes to factory performance. But we’re not most people, and any opportunity we get to bolster what’s under the hood, we take advantage! That said, when it came to the 5.3L powering Jason Scudellari’s Bumpside (yes, you read that correctly!) it already had an ample amount of boost in the form of ProCharger’s D-1X supercharger—putting out 18 pounds of boost at 7,500 rpm, it was already producing a not-so-modest 1,000-plus horsepower. Word on the street had it that by simply swapping the LS coil packs and wires could garner an additional 15-30 more horsepower … at least.

Well, that word came from just off Highway 101 in Ventura, California—home to Granatelli Motor Sports, manufacturers of the Malevolent and Pro Extreme Series of LS/LT ignition coils and 0-ohm OEM replacement high-performance spark plug wires. According to owner JR Granatelli, LS/LT engine owners can expect a “minimum” gain of 8-12 hp with the smaller cubic-inch stock engines—and the bigger they get, the more horsepower achieved. Throw on a turbo or supercharger and those numbers continue to climb (simple fact being, the more need for more spark, the more the coil packs can deliver).

In a nutshell, Granatelli’s OBD-II safe, 50-state legal LS plug wires are, as JR put it, “like jumper cables for the coils and plugs,” manufactured to increase power from coil to plug in upwards of 400 percent! With the average stock/naturally aspirated LS, the wires alone can net in the neighborhood of the aforementioned 8-12 hp; increase the demand for more spark with a forced-induction application and that horsepower gain jumps up to the higher-rent 12-15hp neighborhood! With the addition of Granatelli’s 85,000V Malevolent Series ignition coil packs (50-state legal), stock/naturally aspirated engines can expect an additional 15hp increase, with the forced-induction applications more in the 35hp range. That’s some serious word on the street, so we had to see for ourselves if there was any truth to these shocking claims!

So, instead of simply bolting on said coils and wires and report back to you, Scudellari went a step further: He also obtained Granatelli’s LS valve covers, which he modified to utilize an oil breather/catch can system to accommodate the ProCharger’s boost output. Following the bolt-on procedures, the truck was taken to Westech for a “formal” verification, which ultimately made JR a man of his word with a total combined 35hp increase, upping Scudellari’s real-world, rear-wheel output to 1,043!

2. Along with silicone gasket and mounting hardware, the Granatelli LS covers feature an integrated internal oil baffle.

3-4. If you take a closer look at the second lead image, you’ll notice an Earl’s male -8 AN x male 1/2 NPT fitting; part of our installation entails the facilitation of an oil bypass recovery system to accommodate the supercharger’s 17 pounds of boost! On the valve cover side, that required the drilling/tapping of a 1/2 NPT hole top center …

6. While Granatelli offers the LS valve covers already powdercoated, knowing we’d be making a bit of a mess prior to installation, we started with the plain cast versions and simply had them coated “post mess”!

8. Before the gasket-prepped covers were bolted onto the engine, Jason Scudellari pre-fit the stand-off rubber mounting seals.

9-10. No “messing” with tacky gaskets or the like—literal plug-and-play straightforward install procedure here!

11-12. And there’s no science behind the mounting of the Granatelli LS coils, either—since they’re direct OE replacements, they mount onto stock valve covers with no modifications and/or adapters. Unlike the OE coils though (which are 50 kV), the Malevolent Series pack a whopping 65 kV to the plug!

14. All said … and almost done! While the ignition portion of the job is complete, Scudellari still has to tend to the oil breather/catch can system. (The injector rail sheetmetal cover was custom-fabbed prior to the ignition upgrade.)

15. Using Earl’s Ultra Pro -8 bulk hose, Scudellari marked his length from each valve cover port (with each respective PTC fitting assembly preinstalled) to his intended location on the firewall for the catch can.

17. With the oil lines cut to length, the -8 catch can connector fittings installed appropriately, and …