Rob Matheis’ 1965 Mustang was built by his company Matheis Race Cars in Missouri. The Mustang rides on a tubular chassis (SFI 25.1) with a strut front suspension and 4-link rear suspension. The engine is a twin-turbo 354 ci HEMI V8 making 1,000-1,200 hp but is capable of 1,400 hp. It features an aftermarket steel crank, Ross pistons, H-beam rods, Hot Heads aluminum heads, and two Precision 66 mm turbochargers. Behind the motor sits a Turbo 400 automatic transmission and 9-inch rear end with 3.90 gears and 40-spline axles. You can read more details in Dragzine’s article
Source: Matheis Race Cars FB page, Holley, and Dragzine