Front of crank should be the same as your 8BA or Merc crank. '39 up pulleys and all else in that area fit any '39-53 crank. With 8rt pumps, you will have to use '48-52 F1 pulley or '49 only Ford car or Merc. All late type pumps have sheave out too far to use the inner sheave of pre-49 pumps in order to clear distributor shaft. With 21A ignition you can use '37-48 pumps and get everything up there shorter if that is a concern. You would just need to tap and plug the topmost water pump hole in block, which is a bypass leading to thermostats.
