Yes, the 1954 (and 1955 first series truck) 235/261 would be the best engines for a swap; however, they would not be "perfect". (I am being silly) The groove on the harmonic balancer (and generator - not part of the engine) are narrower in 1953-55st.
Use the 1954 distributor (and, carburetor, if it fits your intake manifold).
Use the 1946 clutch housing and whichever flywheel and clutch assembly and throwout bearing (as a matched set) that look better.
The 54 has a generator on it.
Though if need arose can the 46 harmonic balancer be put on the 54?
Can the 54 generator have the 46 pulley put on it?
The 54 has a distributor and manifolds with carburetor so I don't see the need to use those 46 parts.
Why use the 46 clutch housing? The 54 also has the clutch housing with the foot start so I would think I it should work.
