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.
