Sorry: clutch housing (the term used in the Shop Manual) = bell housing
If the engine you are using came out of a 1950 pickup and that pickup had the original engine rear motor-mount frame cross-member, the clutch-housing (and rear motor mounts) should match your truck.
Can you post of photo of your clutch-housing - to let us know/see if it has motor mounts that are
orientated flat or at an angle) (this change from flat to angled in 1954).
If in doubt, use your 1950 clutch housing with your 1950 clutch assembly (assuming that you are using the original 6v starter that matches the 1950 flywheel).
You could use the 1955 flywheel with a 1950 6v starter if it is an early 1955 engine (they were 6v in trucks). Late 1955 truck engines had 12v electrical system and the starter/flywheel had a different number of teeth compared to a 6v starter/flywheel.
