I had a '70 440 6 pack 'Cuda for 13 years. It was a driving resto-in-progress as it was both my daily driver and foolish youth car. The entire drivetrain was out of a Dodge while the original 440-6, 4 speed, track pack Dana drivetrain was very very very slowly being rebuilt, one paycheck at a time. It had a 2.76 rear, a 440-4 and 727 auto out of another car. The 160mph speedo was not calibrated, but the 8K tach was accurate. I ran M50-14 Pro-Trac belted tires on the rear (26.5" diameter).

I ran a guy on I-75 with a '69 Camaro SS. There is no doubt his car was quicker. After a few miles, my speedo was hovering near the peg and he could not gain on me. I could see the fuel gauge creeping down, and the lane dividers looked like strobes, and the steering wheel did not feel well connected to the front tires.

Using any online calc with 5500 RPM redline, diameter of rear tires, 1:1 3rd gear and 2.76 rear (it would handle more than 5500 rpm for a while, and did...stock fuel delivery was better) it will calc out to about 157 mph top end. I do believe the car actually made it there once. I needed three lanes of pavement to keep it on the road and never tried that again.

Another 'Cuda, my '74 318, was caught in a severe storm. I had gone up to Ubly to drag race, but it was called off due to a severe thunderstorm warning. My drive was about 50 miles down a two lane highway with deep (8') ditches on both sides between cornfields. I was driving about 75 straight south, and the wind came up from the south and lifted the front of my car to the point that I had zero steering due to lift. I braked hard (always be sure that your rear brakes are properly adjusted) to drop the speed, and had to stay under 50 the rest of the way home due to gusts. Weather reports later claimed 65 mph gusts. With lift like that at an effective 140 during gusts, I do believe that the '70 was going quite a bit faster.

I am absolutely sure that the factory 3.90 in the 440-6 would have limited me to 115-120 tops. Although anyone could beat me off the line, in the long run I could cruise right on by and even hit kickdown at 80+ mph.