In hillclimbing, Hepworth competed in a Repco-Brabham before turning to a self-constructed Hepworth-FF four-wheel drive special. With this car he won the British Hill Climb Championship in 1969 and 1971, in the latter year also becoming the first driver to break the 30-second barrier at Shelsley Walsh.
He drove a BRM-Chevrolet P154 (and later a P167) in Interserie racing (a European version of CanAm) between 1972 and 1974. Years later, a team run by Hepworth obtained the last BRM, the 1979 P230, and had it modified to CanAm spec, but the car was crashed and damaged by their test driver before it could be raced.