This 1969 Mustang Mach 1 called “UNKL” was built by the Ringbrothers in Spring Green, Wisconsin. The car’s heart is a 520 ci Boss Nine V8 built by Jon Kaase Racing Engines making 700 horsepower. Behind the V8 sits a Bowler six-speed manual transmission, QA1 carbon fiber driveshaft, and John’s Industries 9-inch rear end with 3.55 gears. The Mustang rides on a Detroit Speed Aluma-Frame front and QUADRALink rear suspension with RideTech coilovers and Baer Extreme six-piston brakes.
Source: Ringbrothers FB page and Holley Garage