The Thunderbolt teams and Ford management were not happy being outclassed by the perceived weak sister Lincoln-Mercury Division.

Unlike the bureaucracy of Ford Division’s racing program, Lincoln-Mercury was a lean and nimble two-man operation.

 Unlike Ford Division, which had to race its engines as prepared by Engine and Foundry, Lincoln-Mercury quickly improved the breathing of its 427s by using Crane cams and Jardine headers.

https://www.hotrod.com/articles/1964-ford-fairlane-thunderbolt-1965-mercury-comet-cyclone-represent-ford-drag-racing-history-mid-1960s/