The Beginning of the Idea of the Shelby Mustang
The rules in the mid-sixties in SCCA racing were pretty strange. Carroll Shelby's AC Cobras were cleaning up in A Production and Corvettes were doing the same thing in B Production. Ford didn't really have anything like that to compete in B Production, and were wishing they did, as Corvette sales were going through the roof.
Then along came Porsche. At the time Porsche sales were slow. They could have easily have entered A Production and competed with the Cobras but that wouldn't have got them sales. So, what Porsche did was enter their cars in the Trans Am and SCCA Sedan class.
You'd wonder how a car with only two seats could get away with being allowed into the Sedan class, but what Porsche did was bend the rules a little by putting a very thin disguise of a seat in the back, enough for two race car scrutineers to sit in with a little bit of headroom and whoa - the scrutineers said, sure, this is a sedan. It was a long couple of years for the top manufacturers until the SCCA rule makers finally decided they'd made a mistake and threw Porsche out of the class, but that was after they'd blown everything else to the wall.
Bizarrely, in a very courageous move, Carroll Shelby, the big Texan chicken farmer, wanted to enter the Sports car class and go head to head with Porsche.
1966 Shelby Mustang
Shelby GT-350 Production
Shelby had a good relationship with Ford. Ford had had the new Mustang in production for about eighteen months in the notchback version and then produced the first fastbacks in 1965. All these cars were, was a Ford Falcon with a longer bonnet. The platform they were riding on was exactly the Falcon's.
So, Shelby took a couple of them off Ford and started chopping them around a little. He got rid of as much weight as he could, and for Sports Car Racing, he did the opposite of Porsche. He took the backseat out and replaced it with the spare wheel. In this format the scrutineers agreed that it was a sports car. He then entered the Mustang into B Production going head to head with the Corvettes, and he beat them hands down all through 1965, 66 and 67.
He was doing pretty well at the time producing the 289 cu-inch and then 427 cu-inch V8, AC Cobra's, in fact selling just over 1000 of them. Then he began producing right next door to them the Shelby Cobra GT350s. He made track and street versions. He simply grabbed them off Ford's production after they'd being finished and pulled any unnecessary bits out of them. He put a great big sump on the 289 V8 motor, which as standard had 271 hp. He then put on his own high-rise manifold, a four-barrel carburetor, and Shelby fabricated headers. That pushed the power up to an easy 306 hp. That was for the street versions. But for the track versions, they simply bolted the Cobra 289 V8 straight in which was already giving 360 hp. That's where the GT-350 name came from. These motors could easily put out an unreliable 400 hp with a bit of coaxing.
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Brakes, Transmission and Differential
He left the Borg Warner four-speed transmission alone. He replaced the rear axle and diff with the much stronger Fairlane one. They got bigger rear drums and discs on the front. The front suspension mounts were relocated for much better handling and then they got Koni adjustable shocks front and back. The bonnet was replaced with a fibreglass one with quick release pins, and the rear side fake vents on the fastback were replaced by plexiglass which looked a whole lot better. You could also opt for a nice set of rear bucket seats instead of the standard slippery bench seat.
Rental Mustang GT-350
Now and again, Shelby Mustang lovers all over the world go down on their knees and say a small prayer to Irving Hertz, for it was he, in 1966, who knocked on Carroll Shelby's door with an order for 1000 Shelby Mustang GT-350's, to be called Shelby-Mustang GT-350H. These were essentially exactly the same car but were painted gold with black stripes. Some were with auto transmissions but a lot were manual. Today, if you can find one, they're worth a fortune. Hard to imagine a collectable rental car and it must be the only model in history to make that category.
During the period though that Hertz owned them. lots of them came back to Hertz with the engine replaced with a standard one and Hertz never knew this until they were getting serviced, so they could never track down the engine thieves. Also, lots were parked up on the sides of race meetings with their engines out for the day getting raced in some special. In fact, its well known that one was used in a Cobra in the 1966 Sebring 12 hour race. So, if you do happen to come across one of these chances of it being matching numbers is fairly remote, but who cares, you've found yourself a real rent-a-racer.
Hertz Shelby-Mustang GT-350H
Shelby Mustang Production
Total production of the Shelby Mustang GT-350 was 562 in 1965 and 2387 including the Hertz cars in 1966. In 1967 he built 3225 Mustangs but these were on a new model which was much heavier than the '65 and '66 cars. They were essentially boulevard racers and none ever saw a racetrack.
In 1968 Carroll Shelby sold everything to Ford and that was the end of their association. So, if you're ever in the market for a Shelby Mustang, don't buy anything other than the 1965, 1966 or 1967 models. All others with his name on were great big bulky fakes.