Ford 272 C.I. runs low 11's. Why do Mopar guys need 408's?

The fun part about that car was when his seventeen year old son came in while we were breaking the engine in.. He had spent his entire life helping his father push that car in and out of the shop and it was the first time he ever seen it actually running...
I personally owned a '63 Fairlane. Fun car, 3 on the tree 170 6 popper