The article did touch on this subject, briefly.
Leo Levine’s The Dust and the Glory is undoubtedly one of the finest histories ever written about the Ford Motor Company in competition. In it we find a reference to another pervasive myth: that a Hertz rental GT350 had its engine removed and installed in a race car, in this case a Falcon being run in the 1967 Daytona 24 Hours. There weren’t many Falcons in that race, and decades after the incident occurred, the little Ford’s owner, the late Ray Heppenstall, was tracked down and queried about the incident. He stated that only the barest essence of the story was correct; yes, he did remove the engine from a GT350H and install it in his Falcon, but the Hertz car was, in fact, one that he purchased the year before after it was wrecked on the Pennsylvania Turnpike. A former rental GT350, yes, but not one in active service.