All '53-'54 235 full-pressure sedan motors used main inserts with shims to set the clearance. I assume the '53-54 trucks are the same.
The '54 water pump will not fit the '58 block, so you've got to get the custom short-shaft. You will also need a '55-62 fan or an electric unit.
The motor mounts on the side of the engine blocks are different. I think your truck's '54 engine is held in with the front timing plate mount. If the timing plate is different on the '58, just use the '54 timing plate and cover.
Good luck
chip
