This is a 1975 Chevrolet Monza 2+2 with the 4-speed manual transmission. It originally belonged to Paul Allen, the co-founder of Microsoft, and after his passing in 2022 it passed into new ownership – and was promptly turned into a sleeper.
The car is now powered by a 383 stroker V8 built by JBA Speed Shop in San Diego sending power back through a 4-speed manual transmission. It’s now far quicker than it ever could have been stock, and the exterior has been kept low-key, offering few clues to what lies beneath.
This is a 1975 Chevrolet Monza 2+2 with the 4-speed manual transmission. It originally belonged to Paul Allen, the co-founder of Microsoft, and after his passing in 2022 it passed into new ownership – and was promptly turned into a sleeper.
History Speedrun: The Chevrolet Monza
The Monza name has been used on five different model series over the past six decades – initially it was a sporty Corvair trim, then an American subcompact, then a Brazilian family car, followed by a Mexican sedan, and finally, a Chinese sedan.
The North American 1975 to 1980 H-body coupe is the one most think of first, it was launched at a time when Chevrolet was trying to give the Vega program a more upscale, more sporting look without spending the money on an entirely new underlying platform.
That car earned the coveted Motor Trend’s Car of the Year award on its first year on sale, and a little unexpectedly, it became one of the most successful American challengers to Porsche in IMSA competition.
The Origins Of The Corvair Monza
The Monza name first appeared in the spring of 1960 as an upscale trim on the rear-engined, air-cooled Chevrolet Corvair. Introduced as the Monza Club Coupe, it added vinyl bucket seats, carpeting, brightwork, and a floor-mounted shifter to the otherwise fairly simple compact.
Sales were strong enough that Chevrolet grew the Monza line for 1961 with a four-door sedan and a 4-speed manual, and by that point the Monza accounted for roughly half of all Corvair sales. The Monza Spyder followed in 1962 with a 150 bhp turbocharged flat-six, one of the first American series-production turbocharged road cars.
The Chevrolet Monza earned the coveted Motor Trend’s Car of the Year award on its first year on sale, and a little unexpectedly, it became one of the most successful American challengers to Porsche in IMSA competition. Image courtesy of General Motors.
When Chevrolet needed a nameplate for its 1975 subcompact, “Monza” was already familiar to buyers as shorthand for a sporty small Chevrolet.
The New 1975 Monza
The 1975 Monza was introduced in September of 1974, built on the H-body platform shared with the Chevrolet Vega. It was 4 inches longer than the Vega and 180 lbs heavier, with restyled sheet metal that Chevrolet general manager John DeLorean nicknamed the “Italian Vega” for its passing resemblance to the Ferrari 365 GTC/4. Yes, it was that John DeLorean.
The 2+2 hatchback carried new rectangular headlights in a slanted nose with a slot-style grille, and the side window louvers were part of a functional “flow-through” ventilation system.
The car was originally designed to house GM’s licensed NSU Wankel rotary engine, and was internally referred to as the 2+2 Rotary during its development. GM President Ed Cole postponed the Wankel program on September the 24th, 1974, due to the emissions and fuel economy problems of the engine.
This decision had knock-on effects across the industry, since AMC had been planning to use the same engine for its 1975 Pacer.
As a result of this, power for the Monza came from the Vega’s aluminum-block 140 cubic inch (2.3 liter) inline-four, rated at 78 bhp at 4,200 rpm with a single-barrel carburetor, or 87 bhp at 4,400 rpm with the two-barrel setup. The more interesting option was Chevrolet’s new 262 cubic inch (4.3 liter) V8 with a Rochester two-barrel, rated at 110 bhp at 3,600 rpm.
The 1975 Monza was introduced in September of 1974, built on the H-body platform shared with the Chevrolet Vega. It was 4 inches longer than the Vega and 180 lbs heavier, with restyled sheet metal that Chevrolet general manager John DeLorean nicknamed the “Italian Vega” for its passing resemblance to the Ferrari 365 GTC/4. Image courtesy of General Motors.
It was the smallest-displacement V8 Chevrolet had ever offered. For California and high-altitude buyers, and for 1975 only, Chevrolet substituted a 350 cubic inch (5.7 liter) V8 detuned to 125 bhp on a two-barrel – the V8 fit was tight enough that some spark plugs could not be changed without partially lifting the engine out of the car.
The Monza also introduced GM’s first use of a torque arm rear suspension, a layout that later appeared on the 1975 Cosworth Vega, as well as on later Vega and Astre models, and eventually the third and fourth-generation Camaro and Firebird.
In April of 1975 Chevrolet added the Monza Towne Coupe, a notchback with a conventional trunk, single round headlamps, and its own rear sheet metal. It was 1.5 inches shorter and 135 lbs lighter than the 2+2, aimed at buyers who might otherwise pick a Ford Mustang II Ghia, and it outsold the 2+2 hatchback in 1975.
A budget “S” 2+2 arrived mid-year with the one-barrel four and a 3-speed manual, deleting the sport suspension, console, sport steering wheel, and other trim to hit a lower price. The Monza 2+2 was named Motor Trend’s Car of the Year for 1975, chosen over the Mercedes-Benz 450 SE, Ford Granada, Chevrolet Nova LN, and Volkswagen Dasher – a mixed bag of competitors if ever there was one.
The Monza’s Wild Success On Track
IMSA’s new All American Grand Touring (AAGT) class opened the door to the Monza in 1975. DeKon Engineering, founded by Lee Dykstra and Australian driver Horst Kwech, built a run of tube-frame Monzas around small-block V8 power.
At around 2,400 lbs and eventually producing 600 to 650 bhp with fuel injection, the DeKon Monzas took Al Holbert to the IMSA Camel GT championship in 1976 and again in 1977, beating Hans Stuck, Brian Redman, and Peter Gregg along the way.
By 1980 the lineup was down to the Iron Duke four and the Buick 231 V6. Chevrolet discontinued the Monza at the end of the 1980 model year, with the front-wheel-drive Cavalier taking its place for 1982. Total H-body Monza production reached 731,504 examples – not a bad figure for this market segment at the time. Image courtesy of General Motors.
Fourteen DeKon chassis were built between 1975 and 1977, and Porsche 935 dominance took over the series from 1978. Chevrolet reportedly used CAD tools in the Monza’s development, an early application of the technology at GM that carried over into DeKon’s chassis work.
The Monza’s Slow Goodbye
The Spyder equipment package arrived on the Monza for 1976 on the 2+2 hatchback and Towne Coupe, joined by separate Z01 performance and Z02 appearance packages on the 2+2 for 1977. A wagon was added for 1978. The engine lineup evolved over the run, with the 262 V8 dropped after 1976, a 305 cubic inch (5.0 liter) small block available in later years, Buick’s 196 and 231 cubic inch V6s, and eventually the Pontiac-built 151 cubic inch (2.5 liter) Iron Duke four that would become notorious in the later Pontiac Fiero.
By 1980 the lineup was down to the Iron Duke four and the Buick 231 V6. Chevrolet discontinued the Monza at the end of the 1980 model year, with the front-wheel-drive Cavalier taking its place for 1982. Total H-body Monza production reached 731,504 examples – not a bad figure for this market segment at the time.
The 383 V8-Swapped 1975 Monza Shown Here
This 1975 Chevrolet Monza 2+2 has an unusual chain of ownership, to say the least, it was originally owned by Paul G. Allen, the co-founder of Microsoft, and was bought by its next owner after his passing in 2022. It later sold in 2023 to C Van Tune, former editor-in-chief of MotorTrend.
A 2015 refurb under Allen’s ownership saw the body stripped, repaired, and repainted in Light Blue, and the interior re-trimmed in black leather with a color-coordinated headliner and carpets. The brakes were converted to power-assisted four-wheel discs on five-lug hubs, and the suspension bushings, ball joints, pitman arm, and tie rod ends were replaced.
The car has quad headlights, sport mirrors, chrome bumpers with black rubber guards, and hood louvers that were added under current ownership. It rides on chrome-finished American Racing 15 inch wheels shod with 195/50 Dunlop Direzza ZII tires up front and 225/60 Forceum Hena tires at the rear.
A 383 cubic inch Chevrolet small block V8 built by JBA Speed Shop in San Diego was installed under current ownership, fitted with AFR aluminum cylinder heads, a Mallory electronic ignition distributor, an oil cooler, and chrome accessories.
Power is sent back to the rear wheels through a 4-speed manual transmission, and a reconditioned differential was installed during the build. Inside, instrumentation consists of a 120 mph speedometer, tachometer, and supplementary gauges, and a retro-style digital media receiver powers Custom Autosound speakers mounted in the cargo area.
The car is now powered by a 383 stroker V8 built by JBA Speed Shop in San Diego sending power back through a 4-speed manual transmission. It’s now far quicker than it ever could have been stock, and the exterior has been kept low-key, offering few clues to what lies beneath.
The car is now a sleeper in every sense of the term, it’s also rare in that it’s a Microsoft-related item that’ll never leave you facing the Blue Screen of Death or needing to bust out your Ctrl/Alt/Del.
It’s being offered for sale out of San Diego, California with refurbishment records, manufacturer’s literature, and a clean Montana title. If you’d like to read more about it or place a bid you can visit the listing here.
Images courtesy of Bring a Trailer + General Motors
Articles that Ben Branch has written have been covered on CNN, Popular Mechanics, Smithsonian Magazine, Road & Track Magazine, the official Pinterest blog, the official eBay Motors blog, BuzzFeed, Autoweek Magazine, Wired Magazine, Autoblog, Gear Patrol, Jalopnik, The Verge, and many more.
Silodrome was founded by Ben back in 2010, in the years since the site has grown to become a world leader in the alternative and vintage motoring sector, with well over a million monthly readers from around the world and many hundreds of thousands of followers on social media.
