Can i put a torino frame on a 1972 mustang fastback?
Forget it, not gonna happen !! There IS no easy way - If you want the repair to last......
The Mustang is (and always has been) a unibody car. That's why Ford could build them so cheaply before unibody became an industry standard.
When you have frame damage to a vehicle, you have to bend, straighten and weld until the repair is finished. Spot welding won't last very long. After you hit too many potholes, the spotwelds will crack and break, then you have to start all over again.