Modified Mustangs & Fords
1968 Ford Mustang Fastback Legal
10.6 At 138 MPH And Street Legal
To drag race, road race, autocross, and be streetable in one ride is a dream. Jeff Hinkle appears to have made the dream come true with his '68 fastback. A best e.t. of 10.38 at 138 mph is just one piece of evidence. On purchase, his Mustang was a "simple correct original." And now, to most of the world, the result is a custom Eleanor/Shelby type clone. But, the Marietta, Georgia, enthusiast did not go wild just to impress. Actually, to tell the truth, the looks were not the top priority on Jeff's list; though he did want a racey body style. He chose an Eleanor-type kit because of its relative easy accessibility in the aftermarket. "We tossed it on to get it done," Jeff tells us.
Now, Jeff could get on with the important part of the build, defined as pure performance, with his dad, Harry. The Eleanor frontend cut across the intercooler, so they chopped part of the fascia off. In every phase of the build, performance took precedence over style and then defined the style. "Same thing with the hood," Jeff said. They cut and raised the fiberglass hood for several reasons. One was to blow cool air over the high-rise intake manifold. Two was to exhaust hot air out of the engine bay at speed and rest. When the driver turns off the supercharged 427 after a hard run, the heat rises up and out of the engine bay through the openings in the hood. Jeff calls this the "chimney" effect. Trapping heat under a fiberglass hood does more than stifle cooling. Heat tends to warp fiberglass.
The Keith Craft custom-built 427 FE (bored and stroked to 482 cubic inches) can generate enough horsepower to warp lots of things-like space and time. Hinkle chose a new Shelby aluminum 427 block topped with Edelbrock heads and requested the strongest internals possible to "over build" the build. Jeff said, "All the internals are billet. We wanted to over build the engine so we wouldn't break it or have problems down the road." In Jeff's experience, too many racers build engines "to the edge of where they want to run it." If they make a mistake then the consequence is they break something major. His game plan was to spend the money up front and over build. Then, if he made a mistake, he would "break little parts instead of major ones."
So far, nothing has broken. The 427 is hardly even pumped up with the Pro Charger F1-R centrifugal blower, as tuned. Horsepower to the crank is 900; the rear wheels handle 720. That's on pump gas. Maximum boost can turn up the wick to 1,300 hp. For more cooling, Jeff cut out a section of the inner fenderwell and installed a grille. The ProCharger F1-R supercharger pulls air right out of this fender opening.
As old school as this build may appear, Jeff went with 21st century fuel injection. He said old school engines were hard enough to start on carburetors. With fuel injection, he could turn the engine over three to four revolutions and light the cylinders. He didn't want to worry about a choke and slow starts. Fuel injection also allows for more precise distribution of fuel, which is good for a supercharged hot rod big-block making this kind of power.
JBA headers hook up to Flowmaster mufflers and separate 3-inch exhausts, negating the use of an H- or X-crossover. "I think it sounds better versus the X-pipe," Jeff says. Each exhaust flows into a side pipe custom-built into the bodywork and exiting in front of the rear wheels.
Right now, the TKO-600 five-speed is coupled to a set of 3.23 gears in a Detroit-Locker differential. The rearend is a stock, old school Ford 9-inch. Jeff plans to install a second set of gears-3.70s in a Detroit TruTrac for use on different tracks. Jeff tells us, "That full locker is a little unforgiving sometimes."