Say “UNKL”: 700hp Mustang Mach 1 widebody

by | Nov 8, 2019 | 0 comments

Ringbrothers unveiled its newest, one-of-a-kind Ford Mustang, a 1969 Mach 1 widebody build known as  “UNKL” powered by a 520 cubic inch 700 hp Boss engine at the SEMA Show.

“UNKL” is the first Mach 1 to leave the Spring Green, Wisconsin, shop after a series of memorable Mustang builds. The widened body and unique race-inspired theme make the most of road and race technology in one car.

The build was being featured in the Flowmaster booth at the SEMA Show.

“UNKL” is powered by a 520-cubic-inch Jon Kaase Boss engine making 700 horsepower. A reworked Bowler six-speed Tremec transmission backs the high-powered engine, and a QA1 carbon-fiber driveshaft transfers power to the rear wheels.

The Mach 1’s growl comes from a custom stainless-steel Flowmaster exhaust. Prestone coolant keeps the engine at an even operating temperature, while Motul engine oil and gear oil keeps things running smoothly. Custom BASF paint called Big Boss Blue has been laid over a smooth body, which was shaped with 3M products. 


Ringbrothers extended the Mach 1’s body by an inch on each side, which gives it a slightly more aggressive stance than stock without compromising the classic look. The car’s body is a mixture of carbon-fiber and steel panels reshaped by Ringbrothers. Other custom details include billet taillights, reshaped bumpers and trim and engine-bay accessories that were custom machined at the Ringbrothers facility.

The name for the build comes from the Ringbrothers owner who enjoyed a close relationship with his uncle. The build pays tribute to his uncle’s influence on his passion for cars. The race-inspired livery continues that theme and will also serve a practical purpose when the car is used on track. 

mustang mach 1

“UNKL” uses Detroit Speed Engineering’s Aluma-Frame front suspension system with a cast aluminum cradle, custom-tuned steering rack, tubular suspension arms, and custom adjustable RideTech coilovers. The rear is equipped with Detroit Speed’s QUADRALink suspension system and RideTech shocks. Front and rear sway bars are also from Detroit Speed. Stopping power is provided by Baer with huge 6S Extreme calipers. “UNKL” rides on bespoke set of forged HRE Wheels wrapped in sticky Michelin Pilot Sport 4S tires sized 295/35R-19 in the front and 345/30R-20 in the rear.

The custom interior of UNKL by Upholstery Unlimited feels as race-inspired as the exterior with supportive Recaro seats, Ringbrothers billet components, an Ididit steering column, gauges by Classic Instruments and a cabin kept at a comfortable temperature thanks to a Vintage Air Gen IV Magnum evap kit.

For more information on Ringbrothers, the “UNKL” Mustang, and Ringbrothers billet parts, visit


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