In the 1960s, the auto companies used race cars, both NASCAR and NHRA, to promote sales. They would build and give promotional cars to drivers and hope that if they won on Sunday, they could sell on Monday.
The first batch of lightweight racing cars by Mercury was offered in 1964. They were race prepared from the get-go. Mercury produced around 11 A/FX cars in 1964, which went to famous race car drivers like Arnie Beswick, Eddie Shartman, and Dyno Don Nicholson among others. The B/FX Comets of 1965 were built off a 289 engine with 271 horsepower, and used four Webbers. Building up the 289, horsepower on these cars could approach 450. Since these cars weighed in at around 2,600 pounds, the performance was outstanding.
The 'Funny Cars' of today are a result of the cars built during this period. While the cars looked stock, racers began to modify the bodies as well as the engines. Moving the weight forward, changing the wheelbase, and altering the body made these stock cars look 'funny.'