This 1966 Ford F-100 Shortbed Fleetside cruising around Dallas carries a small fender badge that marks it as one of the earliest trucks built on Ford’s Twin I-Beam front suspension, a design that stayed in production under F-Series pickups for three decades. With a small-block Ford V8 and updated air conditioning, it is set up to be driven, not just admired. Read on to find out why two forged beams beat the solid axle everyone else was still using.