Actually , it's the other way around . Even though those engines aren't particularly powerful by today's standards , they were grunty in their day . Particularly the hemi sixes . If anything , their gearboxes let them down .
While some of those engines had a good amount of torque , they ran out of revs easily . Having an auto with six gears rather than three keeps the engine right in the fat part of the torque curve . That's why these modern cars are going with ten speed autos . Especially for diesels which have a much more limited rev range .
I've had quite a bit to do with hemi valiants . You are correct on the performance of the three speed pacers and chargers . However , while they would wind up to big ( for the day ) speeds , they were hopeless off the line because of their gearing . Best thing Chrysler did was put a four speed behind the hemi six . Even better was the celica 5 speed conversion from 20 years ago . Absolutely transformed those cars .
I have one of those in the shed right now . Hemi plus four speed coming out . Falcon Barra six non turbo with six speed auto going in . It will be great to drive .
