1989 Taurus SHO. Kept it about 100,000 miles.
Out in the flat country one early morning, slowed to 5 MPH as I passed a mile marker, smoothly went to the floor, at red line ordinary shifts, and at the next marker, 131 MPH, and still in 4th. Put it in 5th and just let slow down to 60, and back on cruise control. Torque steer was bad coming off lights hard, but at 131, I would have been comfortable with my hands of the wheel, it was rock steady.
Never lost a drag, and 5 liter Mustangs were victims, including my sons. Smoothest engine I have ever had, and excellent gas mileage. Only burned rubber once, hot day on asphalt, and too much throttle as the clutch came in, the smoke rolled out of the front wells and covered the hood, visibility zero through it, clutch back down and up, tires were hitched again, and still won the drag.
The estimate for replacing the heater core was out of sight, as the entire dash, steering, and console had to come out. so sold it in Florida to a guy that was into fast. The air conditioner was fine. The SHO was now 8 cylinder, and nose heavy, so did not buy another.