Muscle car fans love the Shelby 350GT - these classic cars have a phenomenal story behind them, and they can fetch almost a million dollars when sold today (depending on the condition, of course).

In the 196o's Carroll Shelby was hired by Ford to turn their Mustang into a Corvette destroyer in the SCCA's B production class. The competition GT 350 dominated the class for the next three years. Creating the car, Shelby's crew worked out of a small shop in Venice California. A number of modifications were made to 37 Fastback Mustangs, provided by Ford, to turn them into racing machines.

Related: Self-Driving 1965 Ford Mustang To Make History At Hillclimb

So when the original crew that built them (Pete Brock, Jim Marietta and Ted Sutton got) together to create 36 'continuation' cars decades later, gearheads were thrilled because these beasts are a perfect homage to the originals. That said, not everything is exactly the same...

10. Independent Rear Suspension

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In 1965, the team (along with Ford engineering), spent a lot of time testing an independent rear suspension when developing the GT 350 Competition model. Ken Miles tested the set up at Willow Springs in GT350R (5R002). Ultimately the IRS was never approved for competition because Ford decided it was too expensive to put into production. Test driver Ken Miles was also never fully comfortable with it. Marietta, who worked on the IRS project, hunted down one of the four original setups. Based on the Dana 44 rear end, the units installed on the OVC continuation cars are nearly identical to those tested in 1965.

9. Engine Upgrades

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To power the vintage cars the OVC took an original 289ci K-code, 4 bolt main engine block and sent it to the Carroll Shelby Engine Company (who produced the engines for the 1965 cars).  Replacing the old points ignition with a duel point electric ignition gives the GT 350 reliability and better performance. Aluminum heads along with a roller camshaft assists in bumping the small block to around 440 horsepower with an 11.4:1 compression ratio. That is around one hundred more horsepower than the engine produced fifty years ago. A vintage head for a car of this caliber can cost in the neighborhood of $15,000. The aluminum heads save cost and add power. To the purist who doesn't agree with these engine modifications, Marrietta has a response “These modifications are a normal progression that, more likely than not, would have progressed at Shelby’s race shop as well,”

Related: Ford Patents Strange Style of Cylinder Heads

8. Rear Disc Brakes

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Included in the IRS set up are solid rotor disc brakes. Already equipped with front discs, this modification gives the car disc brakes all the way around. The option was never included by Ford due to the prohibitive cost, but was definitely a factor in competition. Chevrolet's Corvette in 1965 and Jaguars B production class E-type model had been running four wheel disc brakes since 1961, so it wouldn't have been totally unrealistic for the original Shelby to do the same.

7. Redesigned Front Valance

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Called to Europe for work on the Cobra Daytona coupe project, Brock left the original team while the car was unfinished, but now some of Brock's original designs are included on the OVC Mustang. These changes to the body of the care were considered better looking and aerodynamically more efficient - although 'better looking' is definitely a matter of personal opinion! Efficiency isn't, however, and the redesigned front fascia gives the car more effective brake cooling than the original and offers better cooling to the engine compartment as well.

6. Redesigned Rear Plexiglass Window

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Another element of the original design that Brock was not pleased with was the original “humpdeck” rear window, so this is another element of the design that has been changed on the OVC models to better match his original plans. The rear glass on the OVC Mustangs has been mildly reconfigured to provide better outward visibility and improved aerodynamics. The ventilation for airflow in the car's interior remains unchanged on this modification, though, and it's small enough that many probably wouldn't even notice the difference.

5. Plexiglass Quarter Window

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Brock also mandated an update to the GT 350 Competition's quarter vent aluminum block off plates. This update already appeared in all 1966 Shelby Mustangs, which added a plexiglass sail panel window that took the place of the ‘65’s vented gills or the Comp’s metal block off plates. It may seem like a small change, but it is a very visible one... and speaking of visible, it does make a difference to visibility for the driver; definitely something that everyone wants more of.

4. Emergency Shut Off

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Some of the changes made to the OVC Mustangs aren't because they were part of the original designs or something that the team had always wanted... but because the rules and regulations around vehicle safety has come a long way since the original cars were made in the '60s. An emergency shut off switch was not available on the original cars. For compliance with track safety standards and driver safety, the switch was added to the continuations, along with updated driver restraints.

Related: 20 Safety Features That Actually Make Driving More Dangerous

3. Fuel Tank Bladder

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More updates for safety regulations... The original GT 350 competition model's fuel tank consisted of two stock Mustang tanks welded together. Priding themselves on keeping the car as original as possible, the OVC did not want to install an aftermarket fuel cell, but could not safely run a car on modern race tracks without updating the design. They chose to fabricate the tank in the original fashion on the outside, and used a foam-filling and fuel bladder on the inside. The design allows the car to keep an original look while keeping in line with modern safety standards.

2. Fiberglass Rear Bumper

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Originally dumped to cut down on weight, the competition GT350 did not have a rear bumper. To clean up the look of the OVC's car, the rear bumper was reintroduced, but the decision was made to add the new rear bumper in fiberglass to keep weight down. Painted in white with matching blue stripes it gives the car a more complete and streamlined look that is still inkeeping with the original design that gearheads love.

1. Rear Brake Cooling Ducts

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Rear brake vents were included on a number of the competition GT 350s in 1965/66, but like a number of other designs on the car, they were rushed out to the track before they were fully completed.  Sutton hand builds the high-flow rear brake vents on the OVC GT350, allowing more air to cool the brakes. This provides better performance and extends the life of the brakes.

The OVC mustang is by far one of the meanest continuations on the market improved by the team that built the car fifty years ago. I would like to thank Jim Marietta for taking the time to answer questions to accurately write this article. If you want to see and learn more about the OVC GT 350 Competition you can find more pictures and information at OVCMustangs.com