Ford produced an engine with two overhead cams (one cam per head) and hemispherical chambers in the mid-1960s. The engine, displacing 425 cubic inches and belonging to the FE family of Ford engines, was known as the "427 SOHC"; it was also known as the "Cammer". It was a set of SOHC hemi heads that bolted onto Ford's FE engine block. The 1964 engine was designed in 90 days of intensive engineering effort for use in racing. The 427 SOHC used the side oiler engine block modified slightly to deal with the missing in-block cam among other OHC issues. Because of their power levels, and the fact that Chrysler had showed Bill France that a DOHC 426 Hemi was in the works, it was banned from NASCAR races, though allowed in certain drag racing classes. After the NASCAR ban, Ford continued to produce the SOHC, selling it over the counter to racers and others who used it to power many altered-wheelbase A/FX Mustangs and supercharged Top Fuel dragsters. Connie Kalitta, Pete Robinson, and "Snake" Prudhomme all used the engine in their Top Fuel racers. In 1967 Connie Kalitta's SOHC-powered "Bounty Hunter" won Top Fuel honors at AHRA, NHRA and NASCAR winter meets, becoming the only "triple crown" winner in drag racing history. Dynamometer results of the day showed the SOHC Hemi producing almost 700 hp (522 kW) in crate form (100 hp per liter). The overhead cams meant that it was not as rpm-limited as the Chrysler Hemis were with their pushrods and heavy and complex valvetrains.