Even casual enthusiasts know the story of a Texan racer who shoehorned an American V-8 into a sprightly British roadster and made automotive history.

While the saga of the car offered here does indeed revolve around an AC Ace, its stars are not Carroll Shelby and Ford horsepower—but rather, the inventive and enterprising engineer Dr.

Frank Morgan and a Buick motor.

Dispatched from the AC works in September 1955 to American Joseph H.

Dressel, this Ace was the first of its kind to race in the 12 Hours of Sebring.

Although two additional ACs are noted on a preliminary entrant list for the 1956 race, it was only this car, wearing #37 and driven by Dressel and William Woodbury, that qualified and started—ultimately finishing 4th in class and 18th overall.

The car’s next chapter began when it was purchased by Frank and Mary Morgan for a total of $2,795 in August 1958.

Shortly afterward, Frank corresponded with Dressel about a replacement for the Ace’s original six-cylinder, with Dress...