I recently read that Smokey Yunick(spelling) did that to the Chevelle he owned in Nascar in the late 60s.
Drag racing is a different animal than NASCAR. Smokey Yunick was just one of the drivers that spit in the eye of the regulations regarding their cars, although probably the best at it. Early drag racing was always a no holds barred event. Since altering a drag car only moved it up a class or two, many racers tweaked their rides to shave a few tenths of a second off the time through the traps. I hung out with the Simpson brothers in 1969 and 70 down in Florida when they were chasing some of the stock class records, (”I” Stock at 12.82 in a 1967 Chevy Caprice wagon, and “V “Stock in a 1961 Chevy wagon, LOL), and got to know a few of the better drivers on the 1970 era circuit.