I have 2 good friends who both bought new a '70 383/4spd cuda and a '71 340/4spd challenger. Back in the day, I clearly remember riding in both & they were both 'buzy' even in the passenger seat, especially Gary's 340 car. They both rode in my rr and commented on how smooth it felt. At the time, I attributed it to maybe being 4spd cars. Who knows?