When are you too large for an early A body....

Opposite. I had an aunt that retired and bought a brand new 60 something VW bug, She was so small she had to sit on 2 pillows and still looked thru the steering wheel!!!!
Yup I feel that pain. I recently picked up a pair of plymouth Furys this past summer and I absolutely love C bodies but they are too dang big. On tippy toes I am almost 4'8" and I am under 100lbs.
I have wooden 2x4 blocks duct taped to the pedals in my dart.