by 1957 is was going 211mph,
In 1959 it was up to 239 mph,
in 1963 it was up to 252 mph
Yes there are 8 fan belts on that supercharger.
Beatty retired the tanker in 1966, and it was bought and dissassembled and not reassembled until 1997
http://www.rodauthority.com/features/car-features/hot-rods-you-should-know-tom-beattys-1951-belly-tank-lakester/