A 1954 engine should have the timing plate already drilled if it was from a 3100, so it should be a direct swap. Carburetor and starter are no problem. The distributor is something I would look closely at. 1954 is a strange year. Some had cast cams and some had steel cams. It is not a good idea to use a distributor from a steel cam (1951) in a cast cam engine. You can tell which cam you have by the width of the distributor drive gear on the cam. If the drive gear on both engines look the same width then you are good to go.
