1955-1960 manifolds should bolt up.
The manifold ports MAY be larger than the head ports for the 347 truck engine.
Modern carburetors will not fit the pre-1961 manifolds (and the post 1960 manifolds will not fit the pre-1961 heads). This is a good thing. The modern AFB clones will need major surgury to perform correctly on the 347 (primary clusters, secondary clusters, auxiliary air valve, primary jets, secondary jets, metering rods, and vacuum springs will ALL need to be changed)!
If you want a four barrel, find a 1957~1960 Pontiac manifold with carburetor, and rebuild it.
Jon.
