Looking back on the original 427 Shelby Cobra, it was a case of extremes: too quick, too loud, and too much fun. And with too many exhaust emissions. The smog laws of the early Seventies ended the party for muscle cars in general but, thanks to new technology, the good times are here again. 

Shelby Cobra with New-Tech E-ROD Corvette Engine 

While Superformance stepped up to the plate in demonstrating how this new engine can be fitted in a Cobra, it’s actually intended for a wide variety of other vehicles (such as the company’s new Perana and Grand Sport Corvette due out this fall). And the E-ROD’s price is pretty attractive, too: around $9500, plus installation, actually less than some high-performance crate engines with similar outputs yet lacking emissions equipment that’s included with the E-ROD package. 

Why go the extra mile with a smog-legal setup? As much as we appreciate the simplicity of old-school technology, we realize we can’t walk backwards into the future. Not all areas of the country are accepting of vehicles that don’t meet current emissions standards. In addition, modern electronic fuel injection has much to offer from a performance standpoint, despite the fact that you tune it with a laptop instead of a screwdriver. 

Another obvious benefit of the E-ROD is that it sidesteps any concerns about getting your project registered for street duty. Considering all the time and money that goes into a buildup, that’s a comforting thought, especially if you live in an area with stricter laws, or are concerned about potentially more restrictive legislation. 

To get our arms around this modernized mill, we visited Superformance’s U.S. headquarters in Irvine, CA to go through the E-ROD installation in greater detail, and also stomp the throttle to see how it lives up to its power numbers (more about how it differs from a Ford-based V-8 shortly). 

First, though, we should point out some of the challenges when dropping a New Millenium motor into a Sixties-style Cobra. There’s actually quite a bit to that aspect but, fortunately, Superformance’s in-house mechanic Vlado Jancev already had some experience with other engine swaps, and was undeterred by the technical hurdles. 

From purely a packaging standpoint, getting the LS3 block to fit in the cramped engine bay of a Cobra is not that big of a deal, as long as you use the correct mounts (both the plates and the pedestals are different). In addition, Jancev chose an LT1 engine’s one-wire alternator instead, even though it required a custom bracket and belt, because it takes up less room, sits lower for more hood clearance, and costs less, too. 

In addition, he employed a Camaro bracket to secure the drive-by-wire throttle system, along with a different pedal setup. He also had to account for the coolant hoses being located on the opposite side from a typical Blue Oval mill. Despite all these necessary mods, one advantage of the LS3 is that, unlike a Ford engine, there’s no return line for the fuel system, which eliminates having to route a hose back to the fuel tank. 

What’s more of a challenge than the physical fitment is making sure all the emissions components are in their precise locations, and finding space for items not normally used with a carbureted engine. For instance, the air filter has to be a specific distance (10 inches) from the mass-air flow sensor, and likewise the catalytic converters from the last cylinder port (16 to 20 inches). That meant fabricating a custom airbox for the intake, and installing the cats in the side pipes. The CARB-certification number must be visible on the pipes (it’s just a small section of engraving), and the pipe has to be slightly shorter as well, and fitted with two oxygen sensors (before and after the cat). No ceramic coating can be used on the exhaust (engine paint or chrome is okay, though), as it would otherwise clog up the passages in the converter. Even with all of these mods, the appearance is still fairly original. 

Other aspects of the E-ROD install include mounting the engine computer next to a vent to ensure adequate cooling, and locating an OBD II port under the dash for computer diagnostics. The “Check Engine” light is in the fuse box, underneath the fender lip in the engine bay, rather than on the dash, to preserve the classic look. Speaking of maintaining that authentic look, if you plan to use a Smiths traditional tachometer, for some odd reason the dipswitches have to be set to a four-cylinder mode in order to function with the LS3 V-8. And the charcoal canister for evaporative emissions is secured in the right rear wheel well. 

But enough of all these technical tidbits—now for the fun part. What’s it like to drive a Superformance Cobra with a Corvette engine? The short answer is: loads of fun. Sure, the initial throttle response on a LS3 Chevy V-8 feels a tad less torquey than a big-block Ford, but it more than makes up for it through the mid-range and top end. While frying the hides is a common practice for Cobra owners, it’s not terribly efficient and can be a handful if you’re not careful. So a smoother launch does have its advantages. 

The exhaust note is a little different as well, with some extra whine when lifting the throttle. But the brute power of a Cobra still punches through when you want it. So with this new smog-legal E-ROD engine, this Shelby still has the venom you’d expect in Cobra, but now it’s pure poison.