A look under the hood of a GT350 shows the high-rise intake manifold, aluminum valve cover
Tri-Y headers similar to these were standard equipment on the GT350. Contact Doug's Header
A peek in the trunk of this GT350 shows how the Shelby factory firmly anchored the battery
Behind the engine, an aluminum-case Borg-Warner four-speed transmission was installed, and this led to a 9-inch rearend, usually equipped with 3.89:1 gears. All GT350s for '65 had the Detroit Locker differential, and several gear ratios were available.
There were many other differences between the regular Mustang and the GT350. While the V-8 Mustang came equipped with 14-inch wheels, the first GT350s were equipped with 16-inch wheels featuring slotted spokes; however, most of the '65 GT350 cars had 15-inch spoked-style wheels. The good-looking Cragar spoke wheels were available as an option. Proven Koni adjustable shocks were used at all four corners.
Notice the small Mustang emblem in place on the grille on this car, almost the only vestig
Underhood, a Monte Carlo bar tied the shock towers together for enhanced front-end rigidity. On the '65 GT350, the upper-control-arm pivot points were relocated 1 inch below the stock location for enhanced cornering performance. This change reduced body roll and improved the tire contact patch in corners, because more negative camber was made available. Rear suspension improvements included the addition of traction bars and travel-limiting cables for the rear axle. Correct traction bars for a GT350 are still available from Traction-Master, the original supplier to Shelby. To improve balance, most GT350s had the battery relocated to the trunk.
This photo shows the tach and oil-pressure-gauge pod in place on the dash. Notice how this
When compared to the standard Mustang in appearance, the GT350 had most Mustang emblems removed. The exception was one of the small Tri-bar Mustang emblems found on the front left grille. The standard gas cap also remained. A fiberglass hood was furnished complete with a functional hoodscoop. Some GT350 fiberglass hoods had a steel frame. Tony D. Branda offers authentic fiberglass hoods for your replica project. Most '65 cars were white and had blue rocker stripes proclaiming the designation GT350 directly behind the front wheel. Inside the street GT350, things looked fairly stock, with the exception of a pod-mounted tach and oil-pressure gauge. The R-model cars got an interior safety group that included a rollbar, a safety harness, a fire extinguisher, and plastic side and rear windows.
This good-looking '65 GT350 R-model is at speed and shows many of the Shelby Mustang's dis
As you can see, all of the things done to the Mustang by Carroll Shelby were no-nonsense and effective modifications. There isn't a single trick used by Shelby on the '65-'66 models that you can't duplicate for a similar effect. In the power department, he started with the already-potent K-code engine, so don't expect your C-code 289 to jump to 306 hp with the addition of a four-barrel carb and headers. Your stock 289 will wake up nicely with these additions, but to approach the high power level achieved in the GT350 you'll need additional hardware to stand up to the rpm required to produce this kind of power.
The '66 GT350H shown here has the characteristic black paint scheme with gold stripes. It'
With all of the advances made in camshaft and hydraulic-lifter design, you might be able to avoid the solid lifters altogether and still enjoy the same rpm potential. Crane would be an excellent source for advanced-design hydraulic lifters and cam. Likewise, you'd want to have some type of improvement on the lower end, such as was incorporated in the K engine. A nodular-iron or steel crank would be desirable, as well as some improvement in main caps. The K-code main caps were a heavier casting than the normal 289 item, so you may wish to use them. Main-cap studs instead of bolts reinforced with a girdle would be a good and economical way to improve the lower-end strength on the engine you have. Remember, to achieve 300 hp with a 289, you'll need to spin 6,000 rpm and have reliability good for 6,500, which was the redline on the GT350. ARP is a good source for an engine-stud kit.
For '66, several things changed on the GT350. Leftover '65 cars sold in 1966 had the lowered control arms. To reduce labor costs, the lowered arms were not found on the '66 production cars.