I always heard it, and remember it as "a six-four father", but I looked up the lyrics and the lyrics sites are all saying "Impala", which makes way less sense to me than "Father". Impala like the car? Like the animal? How do either of those help with a height problem? If you had a six-four father however, you would also likely be tall.
Which lead me to make this: https://imgflip.com/i/6tigza