3764476 = 1956-1962 car 235 (probably with hydraulic lifters, mechanical lifters also work in it)

F 29 4 = June 29th 1964 (replacement engine?)

Side motor mounts provides more evidence that it is not a 1954 (did car blocks in 1954 have side motor mounts?).

A replacement block could have been put together with any rocker-arm assembly (and matching push rods).