Jerry Heasley January 4, 2018

“We try to take out inherent problems that were always there,” Randy Roberts said. Inherent problems? “Like the OEM brass two-core radiator. It will not flow enough water. It didn’t years ago—they had trouble,” he explained. Consequently, this 1966 GT cools the cockles of its 289 cubic-inch heart via an aftermarket four-core aluminum radiator, readily accessible from Mustang vendors across the country.

Roberts started this restoration—err, build—with a solid collector car, a ’66 Mustang hardtop that came from Dearborn Assembly with the full GT package. For starters, the 225hp 289 four-barrel V-8 is backed by a Ford Top Loader four-speed transmission spinning a set of 3.23 gears in a Traction-Lok 9-inch differential. The list of GT extras adds a quicker steering gear, front disc brakes, side stripes, and GT badges, along with heavier-duty springs and shocks and a thicker front stabilizer bar.

This ’66 Mustang is a real factory GT. Foglights in the grille are part of the GT package.

Roberts kept these features, but made key changes to correct pesky “inherent” engineering weaknesses. The Oklahoman from Claremore has been on a mission that came to him one day at Tulsa’s Mid-America Ford & Shelby convention. Roberts eyeballed mostly late models, but wanted to see more classics.

What Mustang that Ford hath assembled no enthusiast should put asunder from engaging the highways and byways of America. After practicing the concours restoration arts for many years, Roberts now chooses to refurbish classic Mustangs through Muscle Car Rescue [(918) 371-6177], his business in Claremore, Oklahoma, or as his noble Mission Statement reads on Facebook: “Our goal is to take those poor Mustangs left to suffer in fields and driveways and put them back on the road so that everyone can enjoy them again.”

The hood is functional and adds a performance look that looks good on a GT.

This explains a modern Hurst shifter connected to a stock Ford Top Loader four-speed. After a little wear an OEM shifter tends to jam between gears, and the pull handle to shift the transmission into reverse was never a real smooth operator. Roberts also changed out the stock three-finger clutch pressure plate for a new diaphragm clutch, which takes half the pressure of pushing down on one of those original clutches. The GTs came with disc brakes up front. Roberts added a power brake booster and replaced the single master cylinder with a dual bowl unit.

Roberts installed an aftermarket Shelby hood and a Shelby front valance designed to integrate with a stock chrome front bumper—the Shelby valance improves airflow to the A/C condenser and radiator, as well as adding hot looks. The hood is likewise hot looking with a functional scoop for better airflow to the carburetor. Roberts replaced the stock Autolite four-barrel with a modern 600-cfm Holley with an electric choke.

Stock trumpet exhausts exit through the rear GT valance.

Inside, this GT hardtop came with a deluxe interior, which explains the factory-simulated wood wheel and plush bucket seats, both stock. Roberts preferred simple, standard door panels rather than more ornate deluxe. Since this car was built to drive, Roberts replaced the stock AM tuner with a RetroSound digital radio. He feeds leads from the back of the receiver to the glovebox to run an MP3 player through the RetroSound front and rear speakers. This GT came stock with factory air conditioning, but Roberts replaced the factory setup with a reliable and modern condenser and evaporator case and compressor from Old Air Products.

This refurbished ’66 Mustang is still a ’66, but the car is now free of the inherent problems built into the car in the 1960s. Randy explained, “If you want to drive from California to Tulsa to the big show, this Mustang will get you there.”

Styled Steel wheels are 14 inches in diameter and mount modern radials. Roberts went back with the stock power steering system. He said, “When they are right, they are hard to beat. A rack-and-pinion is more modern, but not necessarily enjoyable.”

A Shelby front valance looks great and allows much higher airflow into the fins of the new 4-core radiator and the A/C condenser. GT Mustangs also came without rocker panel moldings, one reason this hardtop’s profile is so sporty. The paint on Randy’s car is stock Wimbledon White with red GT stripes.

The 289 engine runs a Holley carburetor for performance and reliability. Roberts swapped the large and restrictive stock air cleaner for a “High Performance” style open filter element.

Roberts prefers the standard door panels for their look but the rest of the interior is deluxe, including the plusher seat upholstery. Aftermarket air from Old Air Products still utilizes the 1965-1966 factory-style evaporator case mounted under the center of the instrument panel. The steering wheel is OEM correct for a deluxe interior Mustang.

Roberts replaced the metal roof skin, which was vinyl covered and hid rust, with a new one from Dyancorn. “It was pretty easy to change out, and for an experienced body shop the way to go. The old roof had maybe 50 rust holes.”