The Cobra 427 SC modified for race was clocked at 198.something miles per hour at a Le Mans event back in the day. I have pictures of the car that did it. I took my pictures while it was driven locally at a Historic Automobile Race.
They had to modify the nose to keep it on the road. It would tend to lift at speeds above 170 mph. The 289 would do 150 mph and the 427 would do 170 mph stock. This is with the 427 Side Oiler engine and not the 428 police motor.
I've had mine well over 200 on Daytona, but I generally keep the transmission toned down for acceleration on road courses. The thing is a brilliant drive.