Technical The force is strong...38 Chevy help

You can replace your complete front end using a front end from a 49-54 chevy car. Had a friend who had a coupe, conv., sedan and pickup all running these front ends. They are a bolt in.

 

update..I finally installed the 57 6 cylinder. Now I have a bad tranny leak. I cant understand why I have so much leaking? Could I have overfilled the tranny? I made sure it was filled to the top "bolt". It will only leak when I press the clutch otherwise fine when idling. It is coming from the shaft not the plate that holds the shaft in place.

Shifts great runs awesome leaks like a stuck pig. Help!