Just going on what knowledge I have, as I have not done this. The 95 Cobra R has a 5.7L push rod motor. The Lightning motor is a mod motor, so you would need a new K member, from a 96-98 Cobra "might" work, for the motor mounts. It would be major undertaking to get in installed, wired, exhuarst done up, a lot of fabricating.
Another option would be to install a 351 fuel injected and put a Kenne Bell supercharger on it.
BTW, the 95 Cobra R has a 5.8L, not 5.7. But like 94Pace said, you would get much more power and fun out of a supercharged 351W. And it would fit easily in the car.