Remember too that back then the speed limit was 75 , which means everyone was doing 90 just to stay with traffic so where does 140 become unobtainable, unsafe yes, unwise definately but winding these cars past 6000 on a top end run was not uncommon, and the reason more speed wasnt obtauined is because these things drove like a wagon and you had to have a pretty big set of balls to keep your foot into it that long. Like my cuda back then had more to go but I liked living and preffered that the car went where I pointed it and not me go for a ride. At those speeds in those cars in those days there was more speed to be had but nothing more to prove, when you feel these things begin to float and drift you had to back out easily too not just shut it down cuz you were on the ragged edge of driveability. The guy who bought my cuda can attest to that ...if he had lived. When done the cuda would fit on your coffee table