John Roncallo owns a unique 1986 Mercedes 560SL (R107). The car originally came with a 5.5 L M117 V8 making 225 hp and four-speed automatic transmission. At some point the factory powertrain was swapped for one from a 1996 Mercedes SL600 (R129). This means in the engine bay is a 6.0 L M120 V12 making 389 hp and 421 lb-ft of torque. Behind the motor is a 722.6 five-speed automatic transmission and R129 rear differential. The car also received the wheels and front brakes from the SL600. You can read more about the project in the build thread.