The car that combined a British AC chassis with an American V8 engine was the Shelby Cobra.
The Cobra began as the AC Ace, a lightweight British two-seat roadster with an aluminium body and tubular steel ladder chassis. American racing driver and constructor Carroll Shelby wanted to create a faster version, so he arranged for AC to accept Ford’s compact V8 and sent the modified chassis to California.
Shelby’s team installed the Ford engine and transmission in the first prototype, CSX2000, in 1962. The earliest production cars used Ford’s 260-cubic-inch V8, followed by 289-cubic-inch versions. Later Cobra 427 models received the much larger Ford 427 V8 and gained wider bodywork, suspension changes and distinctive side exhausts.
The names can cause confusion. AC Ace identifies the British donor car, while AC Cobra is a historically valid name for the finished hybrid. Shelby Cobra is the canonical quiz answer because Shelby developed, marketed and raced the Americanized version, turning it into an international performance icon. The Sunbeam Tiger and Ford GT40 were different Ford-powered projects.