A 1970 Ford Mustang SportsRoof gets a complete heart transplant on PowerNation’s Detroit Muscle, swapping its original small-block for a supercharged 5.0-liter Coyote V8 paired with a Tremec TKX five-speed transmission. The build leans on ARP fasteners, Detroit Speed headers, and a custom belt-drive system to make the modern powerplant fit a decades-old engine bay. Viewers in the comments debated the real cost of the swap, with one builder pricing out a $305 header alternative to the show’s $3,500 name-brand set. The result is a classic fastback built to run with cars its original engineers never had to worry about.