Sophistication, Meet Power – The LS1-Swapped “Benz-Vette”

bobsmbzls-leadartAs with quite a few breeds of classic car, both domestic and imported, the old-fashioned Mercedes-Benz can be an acquired taste. Many gearheads would agree that a classic ‘Benz is objectively cool (in its own right), but there’s no doubt that it takes a special palate to truly appreciate one – at least for those of us who prefer burnouts, blower-whine, and good ‘ol fashioned American muscle.


On the outside, it’s just another classic MBZ 450 SL. Little do they know…

Bob “The Ring Guy” Sirilla – the same gentleman who gifted us with the coolest damn V8-engine rings we’ve ever seen – has developed just such a palate, and happens to be the proud owner of a truly gorgeous 1973 450SL. However, along with his passion for Mercedes-Benz, Bob also happens to love the unmistakable soul of American machines.

How, then, does he also satisfy his itch for loud ‘n proud American power when cruising around in his land-yacht import? Well, a simple peek under the hood (or earful of the exhaust note) will reveal this ‘Benz’s star-spangled secret.

When it comes to this Mercedes-Benz, the manufacturer’s old motto – “engineered like no other car in the world” – applies quite literally. In place of its original 4.5-liter German V8 is instead the heart of America’s sports car – a 5.7-liter LS1 powerplant.


What used to be a 450 SL is now a 450 LS thanks to the swap that’s been done.

Bob tells us that he first laid eyes on the car at the Spring 2015 Daytona Turkey Run and it was love at first sight. Already having an affinity for classic Mercedes, his attention was captured by the incredible shape that the 43-year-old car was in.

Later, at the Fall 2015 Turkey Run, he encountered the car again and the deal was effectively sealed; upon close inspection, Bob was captivated by the incredible workmanship that was put into the engine-swap. Having many projects of his own, he fully understood what it took to pull off the conversion and he knew he had to have it.

Corvette power under the hood; and pure luxury inside.

To this day, he’s still spell-bound by the car. Bob proudly states, “The 1973 450SL is the most beautiful roadster that Mercedes-Benz ever made. With its upgraded drivetrain, the ‘Benz-Vette’ is perfect in every single way – it’s impressive in how it looks, drives and stops.”


The ultimate sleeper: just an average car with something potent under the hood.

He continues, “The new power to weight ratio is such an incredible improvement; acceleration is smooth, but extremely quick and responsive to the driver’s input.” An LS1 from a 2004 Corvette coupled with the drive-by-cable throttle body of a 2002 Pontiac Trans Am tends to have that effect on most old roadsters – especially ones like the 450SL.

During its development, engineers dubbed the 450SL “der Panzerwagen” (which loosely translates to “real damn heavy”). The car weighed nearly 3,600 pounds dry and churned out a paltry 190 horsepower from it’s 4.5-liter V8 but, after all, it was only a luxury car. With the 350-horsepower, 5.7-liter Corvette powerplant under the hood, however, the stout machine can propel itself around with incredible, grin-inducing ease.


A lot was removed to make room for the LS1, and seeing how much room is left over, it's a great fit.

Bob tells us that the Corvette motor sits very well inside the engine bay, and that everything on it is completely accessible. As for the rest of the drivetrain, a 4L60E stands in for the original 3-speed automatic, but the driveshaft and rear end are as they came from the factory.

The suspension, according to Bob, is where the level of craftsmanship that went into the build truly shows. He explained that the Mercedes suspension was totally removed and a Heidts front frame-clip was installed. He says, “The installation was absolutely professional. The attachment of the subframe to the unibody was so well done that it looks like it was manufactured that way.”


We imagine this is the view most unsuspecting drivers see. Would you know this is anything but a 190HP MBZ?

The upgraded suspension setup consists of Heidts tubular A-arms, a Heidts power-assisted rack-and-pinion, a 1.5-inch Heidts sway bar, and adjustable coil-overs. Outwards from there sit 11-inch rotors with Wilwood brake calipers to scrub off speed.

In the rear, the suspension and brakes are all factory-Mercedes, but everything has received a top-to-bottom refresh, including new springs and shocks and rebuilt brakes. Chrome, eight-window Mercedes-Benz wheels – styled after a late-’90s E-class and sized at 15″x7″ – sit at all four corners. Michelin Primacy MXV4s connect the car to the road and – paired with the revamped suspension and all-new body mounts – offer the ultra-smooth ride quality you’d expect from a Mercedes-Benz roadster.


The interior is all stock, and doesn’t even give a hint that there’s a surprise under the hood.

Despite approaching a half-century in age and accruing over 135,000 miles in its lifetime (3,000 since its rebuild), Bob communicates that all of the original components – which make up nearly the whole car – are in fantastic condition. The chrome and stainless pieces are in good condition, the glass is crystal-clear, both the hard- and soft- tops are in great shape (with the exception of a few scratches and tears), and the dash and seats are far better off than one would expect for a 40-year-old car.

In general, Bob’s “Benz-Vette” boasts an outstanding level of preservation as compared to most other Mercedes-Benzes; it really is quite rare that we see any privately-owned, road-going ‘Benzes in a condition better than mediocre.

As even Bob put it, “I have a lot of garage-rats that need tons of work. This car, however, is just perfect in every way.” We can definitely understand the breath of fresh air that comes with having at least one completed project. But even though its not ours, the “Benz-Vette” serves us as a breath of fresh air, too. In our world, built-up muscle cars are garden-variety (don’t get us wrong – we aren’t complaining), so a change of pace like this unique, off-the-wall Mercedes is welcome from time-to-time.

Needless to say, the car makes for an unusual clashing of two worlds. Even in the land of LS-swaps – permeated with the wildest and most imaginative combinations in the automotive industry – not often do we see the high-browed, slow-but-sure-footed poise of an old-school Mercedes-Benz roadster paired up with the juvenile, speed-hungry, all-American attitude of a C5 Corvette.

The greatest thing about this marriage, however, is the fact that neither of the two main ingredients overpowers the other. The simple, grandfatherly beauty of the German roadster remains completely unmolested, and the performance-minded powerplant is complemented by an appropriate transmission and suspension setup.

All things considered, the “Benz-Vette” isn’t quite what we’re used to – and we love it. What better way to pull of a motor-transplant than by muscling-up our counterparts from across the pond?

So what do you think of Bob the Ring Guy’s American-powered Mercedes-Benz? Is it a well-done product of the ever-prominent LS-swap, or would you pass on the old-school German roadster? Tell us what you think in the comments below.20151216_153937

About the author

Joshua Phillips

Josh has always been captivated by cars, from legendary classics and late-model American muscle to European supercars.
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