They probably had - what - 2.76 gears? I knew some Ga. State Patrol officers back in the mid-1970's who claimed their smog 460 Fords would do 160. I was more than a bit skeptical of that claim. Thought it was funny, though, to hear these law officers bench racing just like any hot rodders I ever knew.
Just calculated 140 mph. Assuming a smog Era 440 could reach rated peak horsepower of 225hp net, at 4400 rpm, the cop car would have to have 2.41s in the back.
Sorry, I don't believe a stock 8 to 1 (or less) 440 can pull a 2.41 gear in an aerodynamic brick to 140. I just don't. Maybe 120, given three or four minutes.