Copied this from an AERA article: A “BOSS” To Reckon With
"Chrysler pegged its efforts on the recently reborn Hemi, Chevrolet relied on the 427 big block “Rat Motor”, and Ford used its 427 “FE” series engines. That scenario put Ford at a bit of a disadvantage because the “FE” was a dated design having originated in 1958; the 426 Hemi debuted in 1964 and the big block Chevy first hit the streets in 1965."
That "dated design" sure has whooped its share of Hemi's and BBC's