The 1977 Chevy With IMSA Widebody Looks And A Wheezing Four-Cylinder

As a society, we are often instructed not to judge a book by its cover. This advice tracks because one Chevrolet car proves that looks can be deceiving. The 1977 Chevy car features an attractive IMSA widebody style, but it doesn’t deliver on its racing aesthetics. There aren’t any performance upgrades to be found under its aggressive style. All you will find are disappointing engine options that won’t secure any first-place racing wins on the track. But this doesn’t stop collectors from throwing money at rare surviving examples.

The DeKon Chevy Monza Was A Racing Success

In the late 1970s, Chevrolet wanted to celebrate the success of one of its race cars in the International Motor Sports Association (IMSA). The DeKon Engineering IMSA GT Monza houses a modified Chevy 5.7-liter small-block V8 engine with up to 650 horsepower and 550 lb-ft of torque.

It can accelerate from 0 to 60 mph in about 4.7 seconds and completes a quarter mile in about 12 seconds with a top speed of about 204 mph, depending on the track gearing. It dominated the IMSA Camel GT Series with three consecutive wins. It successfully embarrassed factory-backed Porsche and BMW racing teams.

But keep in mind that the DeKon Monza only used the roof, doors, and rear hatch of the standard Chevrolet Monza model. It was heavily modified with a custom tubular subframe chassis with a lightweight fiberglass and steel widebody silhouette. It tips the scales at 2,400 pounds, with 17-inch racing tires housed under aggressive fender extensions, ensuring perfect weight distribution for optimal cornering and braking.

At Least The 1977 Chevy Monza Mirage Looks Confident

The 1977 Chevy Monza Mirage got a factory-authorized appearance package to pay tribute to the DeKon IMSA GT model and celebrate its success. The 2+2 hatchback looks great with its unique widebody kit that features confident full-length red and blue vinyl racing stripes and Mirage graphics against white paint.

The aerodynamic additions include molded-plastic urethane front and rear wheel arch flares, a lengthy front air dam or chin spoiler, and a rear decklid spoiler. The 14 pop-riveted reaction-injected molded (RIM) polyurethane panels closely mimic the DeKon Engineering IMSA GT Monza race cars.

To complete the aggressive style, the Monza gained blacked-out trim pieces around the headlamps and grilles. The party continues in the interior with high-back bucket seats trimmed in Forthorn Red vinyl, round gauges with a brushed-aluminum instrument panel, wood grain accents, and a custom sport steering wheel.

But the Monza Mirage Doesn't Pack Any Heat

Mirage is a fitting title for the widebody Monza, as its style is a bit of an illusion. You would expect the race car style to be backed by potent power. However, this car didn’t come with any mandatory performance upgrades. Drivers quickly found out that the race car looks were paired with wheezing engines.

The 140 cubic-inch (2.3-liter) engine delivers 84 hp and 122 lb-ft of torque. It helps the Monza accelerate from 0 to 60 mph in about 12.4 seconds and cover a quarter mile in around 19 seconds with a top speed of 115 mph. So, it was more of a turtle than a race car, but it did eventually get from point A to B.

Drivers were in luck if they wanted a little extra muscle. They could upgrade to the available 305ci 5.0-liter two-barrel V8 engine with 145 hp and 245 lb-ft of torque. This engine helps the Monza accelerate from 0 to 60 mph in roughly 9.6 seconds with a 17.1-second quarter mile time and top speed of about 115 mph.

General Motors Outsourced The Project

You may be surprised to learn that Chevy didn’t build the Monza Mirage in-house. In fact, it wasn’t even designed by General Motors. A small design firm known as the British Overseas Racing Team, based in Grand Rapids, Michigan, engineered the widebody kit. The firm was responsible for designing the Cobra II for Ford, so it’s no surprise that it did a great job.

Chevrolet quickly approved the street-legal homage design. Then it contracted another Michigan-based company, Michigan Auto Techniques (MAT), to manufacture the polyurethane body flares, spoilers, and air dams, and to apply the vibrant racing stripes. Each model started as a standard Monza at the plant in Quebec before being shipped to MAT for purely cosmetic upgrades.

The kit could be added for only $100 to $200, making it a bargain. Some models were available on the showroom floor, but others had to be specially ordered with the RPO ZX1 package. It could be paired with the three-speed automatic or four-speed manual transmissions and certainly looked like Chevy had a hit on its hands.

Then The 1977 Chevy Monza Mirage Faced Serious Problems

General Motors expected to sell between 8,000 and 12,000 models as it waited for the orders to start rolling in. It was so confident in its success that it planned to offer it with more colors in late 1977 and 1978. The car would have been available with black paint and gold stripes, light red with gold stripes, and silver with red stripes.

However, the Monza Mirage never really took off. Automotive historians believe that roughly 2,400 to 4,124 models were made. Overall, about 73,348 Monza cars were sold in 1977, so models with the street-legal Mirage appearance package only accounted for a small percentage. Production was scheduled through 1978, but the special edition was discontinued in 1977.

It didn’t help that the 1977 Chevy Monza Mirage quickly gained a reputation for having severe rust problems. This was a common problem with the H-body platform. However, the bolts on urethane pieces trapped water against the steel body and accelerated decay, leading to hidden corrosion. The unibody chassis is known for rusting through the trunk, floor pans, and lower quarter panels.

Now The 1977 Chevy Monza Mirage Is A Rare Collector's Dream

Many collectors would love to find a rare surviving 1977 Chevy Monza Mirage model without cracks in the body panels or rust. It’s pretty darn unique and exclusive as a one-year-only trim despite being notoriously underpowered. It’s a tribute to the highly successful IMSA Camel GT race cars, providing ties to Chevrolet performance history.

Also, its aggressive widebody kit is extremely nostalgic. The red and blue racing stripes help the car be instantly recognized as an icon from the 1970s malaise era. Ironically, this celebrated time period is associated with when muscle cars were choked out of their potent power, so it's somewhat fitting that the Mirage is famously sluggish.

1977 Monza Mirage models found in fair driving condition fetch between $12,000 and $15,000. Then models found in good condition go for between $15,000 and $25,000. The cars in pristine condition often cross the auction block from $26,000 to over $32,000. Monza Mirage models with the V8 engine and manual transmission command the highest values.

Source: Chevrolet, Scharch, Classic.com