The PCB tracks and terminals will not handle 60 A in still air. A 25 mm trace at 60A has 200K temperature rise, above ambient, and this devide 80mm total width into a H bridge.
From that point, its just a question of the airflow.
About the FETs... Actually it is not that hard to get 60+A fets in TO220, of course you need to keep it cool.
This is my favourite:
"Due to personal measurement technique is different, there may be 1-3 mm error of the physical.Thank you!"
So apparently, length depends on your personal technique.