Curt, there are two different 534 induction systems - the single plane used on Super Duty trucks and the dual plane used on 534 industrial engines later on. The single plane intake manifold looked like a sideways shoebox with one transverse rectangular plenum leading to both heads thru a large rectangular opening at each end. Inside each single plane head was one large passage that looked like the inside of a typical cast iron exhaust manifold. The mixture went from the single intake outlet to the middle of a longitudinal passage in the head that split off into four branches at the intake valves. The dual plane induction system is conventional. Single plane intakes fit only single plane heads, dual plane intakes fit only dual plane heads, there is no interchangeability - not even close. Exhaust manifolds remain unchanged from single plane to dual plane heads.