Mustang Monthly

550hp 1966 Mustang - Modified In Disguise

A stock fastback body conceals the 550hp Roush powerplant in Matt Banks’ sleeper ’66 Mustang

From the September, 2011 issue of Mustang Monthly

By Jerry Heasley

Photography by By The Author

The exterior of Matt Banks' '66 Mustang fastback appears stock except for the wheels. Painted in factory Signal Flare Red, there are no LeMans stripes, scoops, or spoilers. Likewise, the original Parchment Pony interior, code F6, also looks factory original. However, behind the authentic simulated wood steering wheel is a JME billet aluminum gauge cluster fitted with six AutoMeter Ultra Lite gauges, including a tachometer.

Banks' goal with his build was to avoid drawing attention to the modifications. At a glance, his Mustang appears mostly stock. But underneath the sheetmetal is a 550-horsepower Roush 427-R engine, TKO five-speed, Currie 9-inch rearend, and many other modern upgrades to shrink time and distance in the spirit of the original pony.

The build is totally reversible. Banks would not tolerate cutting the chassis or body. This way, he can return to stock if so desired.

An anesthesiologist today, Banks has owned his '66 Mustang for 32 years. In 1979, he was two weeks away from his 14th birthday when he found the "fairly rust-free" fastback sitting in a field near Houston. The price was $1,100. Powered by its factory two-barrel 289 and four-speed, the fastback bore the marks of the hot rodder, typical of '60s Mustangs of that time. Banks recalls that the car had "headers, wide tires on the back, and a double-pumper Holley."

Lucky for Banks, his grandfather built race cars. The two of them swapped out the old 289 for a healthier 302. While the teenager drove his first set of wheels, he helped his grandfather rebuild the 289, but not to stock specifications. Banks recalls a thumping solid-lifter cam, a premium-burning 10:1 compression ratio, and rotating masses carefully balanced and blueprinted.

"I ran that 289 for two years in high school," Banks recalls. "Then, during my senior year, I stored the car in a barn up in Waelder, Texas, where my parents had some property."

In the back of his mind, Banks harbored a dream build. But at that moment, he needed reliable transportation to college so he bought a new pickup. He also followed his grandfather's advice: "He told me, 'This is your first car. Don't ever sell it.'"

So, unlike so many other teenagers of the 1970s, Banks kept his first car.

Later, during medical school, Banks retrieved the fastback. Established with a family and a medical practice, the young doctor was finally ready to put his first car back on the road.

Just two miles away from his home, Banks discovered the shop of enthusiast Virgil Wood in Rockwall, Texas. Wood calls his business CARS, for Classic Auto Restoration Services. Banks did not want to simply drop off his Mustang at CARS and become a "check-writer." Instead, he helped restore the Mustang with Virgil, directing the build and participating in the actual work. The two became good friends.

Banks said, "I would come up with all these crazy ideas. I wanted power rack-and-pinion steering, so I'd research what part I wanted, buy it, bring it to the shop, we'd read the instructions, and install it."

Banks' overall goal was over 500 horsepower with air conditioning, power steering, and power brakes. His Mustang would cruise the streets in comfort, but still hold its own on the dragstrip and around a road course.

The 427-R crate engine from Roush Performance exceeded the 500 horsepower needed for speed. It's not the modular engine from the late-model Roush 427-R Mustang. Instead, the Roush crate engine is an old-school 351 Windsor, bored and stroked utilizing a Dart four-bolt main iron block, aluminum heads, and a 750-cfm Holley double-pumper. Unlike the modular V-8s, this engine fits the '66 Mustang engine bay without cutting or modifying the shock towers.

Banks researched literally "every part" for his fastback. For example, he talked to Roush technicians to determine the ideal rpm for the engine when cruising at 70 mph. The answer was 2,000. After measuring the circumference of the BF Goodrich 245/45/ZR17 tires, Banks calculated that a set of 3.70 gears would yield 2,100 rpm at 70 mph with the Tremec TKO 600 in fifth gear.

A Pro 5 shifter mixes the gears in the Tremec TKO 600 five-speed. Needless to say, the 427-R delivers enough power to "get rubber" in all five gears.

A key issue was the steering. Banks recalls, "The stock steering had a lot of play. Hit a bump and the car would want to go left or right." The solution was Total Control's rack-and-pinion steering. Per procedure, Banks did the research, then he and Virgil installed the part.

With 535 ft-lb of torque, Banks worried about twisting the Mustang's unit body. For added strength, he used a trick his grandfather taught him by welding 1/8-inch plates to each side of the framerails, front and rear, along with subframe connectors.

Banks upgraded the front suspension with Total Control upper and lower tubular control arms and VariShock QuickSet 2 double-adjustable coilover shocks. A 11/8-inch front sway bar with polyurethane bushings helps minimize body roll. The rear suspension features the old hot rodder's trick of 4-1/2 leaf springs with a one-inch drop to reduce wheel hop. This setup supports a Currie 9-inch rear end.

The 17-inch five-spoke Intro Speedstar wheels are obviously custom. From a distance, the front fender badges resemble the old 289 High Performance emblems. However, a close look reveals the Banks/Wood custom touch of "427" inside the crossed flags and silver V.

Because Banks wanted FM without ditching his old AM radio, Antique Automobile Radio converted his original unit to AM/FM with an iPod/iPhone connection.

Although the dream build is pretty much done, Banks stays on top of new developments. He had planned to install a set of Shelby under-ride traction bars, an old trick from the 1960s. Before installation, Total Control came out with a four-link for the rear of early Mustangs. He has decided to install this system instead.

Chances are Matt Banks will continue to modify his '66 fastback. He just won't draw attention to the changes. MM

The 427-R crate engine from Roush Performance exceeded the 500 horsepower needed for speed. It's not the modular engine from the late-model Roush 427-R Mustang.

Specs: '66 Fastback

Engine

427-R Roush crate motor
Dart 4-bolt main block with 4.125-inch bore
Forged 4340 steel crankshaft with 4-inch stroke
Forged 4340 steel H-beam connecting rods
Forged Wiseco pistons with 10.25:1 compression ratio
Double roller timing chain
Roush hydraulic roller camshaft
Roush CNC-ported aluminum heads with 2.08/1.65-inch intake/exhaust valves
Holley 750-cfm double-pumper carburetor
Edelbrock dual-plane intake manifold
K&N air cleaner with Extreme top and custom bottom for hood clearance
8-quart front sump oil pan
Steel 157-tooth flywheel
140-amp single wire alternator
Aluminum water pump
Sanden A/C compressor
Vintage Air Front Runner serpentine belt system
Ron Morris adjustable motor mounts
Powermaster high-torque starter
Custom A/C lines hidden under passenger side fender
MSD distributor with MSD 6AL box and rev limiter

Cooling System

BeCool '68 big-block radiator in custom radiator core support
BeCool dual electric fans

Fuel System

16-gallon Fuel Safe Sportsman Fuel Cell
Holley Blue electric fuel pump with stainless steel fuel lines
Holley fuel regulator
Custom steel bolt-in cover for fuel cell

Drivetrain

Tremec TKO 600 five-speed
Pro 5 shifter
Keisler Engineering hydraulic throw-out bearing
Lakewood scattershield and a SPEC diaphragm clutch
Currie Enterprises 9-inch, narrowed one-inch
3.70:1 gears in a Posi unit with 31-spline axles

Exhaust

JBA ceramic-coated headers
2-1/2-inch dual exhaust with H-pipe
Flowmaster mufflers

Suspension

Front: Total Control Products' coilover front suspen- sion with tubular upper and lower control arms, VariShock QuickSet 2 double-adjustable coilover shocks, and 1-1/8-inch front sway bar
Rear: 4-1/2 leaf springs with one-inch drop and VariShock double-adjustable shocks Total Control power rack-and-pinion

Brakes

SSBC front and rear discs with Hawk HPS brake pads
SSBC power brake booster with dual chamber master cylinder
SSBC vacuum pump for power brake booster

Wheels & Tires

Front: Intro Speedstar 17x7-inch wheels with BFG G-Force Sport 215/45ZR17 tires
Rear: Intro Speedstar 17x8-inch wheels with BFG G-Force Sport 245/45ZR17 tires