They made them at http://www.timemachinesinc.com/pastcustoms/71vipercuda/ 6 years ago, just an extra floor structure, wheel tub work, and add a couple inches to the Viper frame rails to extend the wheel base for the cuda wheel locations.
Wrecked Vipers are the speciality of X2 Collision in Maryville Illinois http://www.x2builders.com/default.asp