Transmission change in 1950 F1 Question

[oneoldtruckguy]

I have a 1950 Ford F1 with a original Flathead V-8 and a Non Syn 4-speed tranny. I just bought a Real Nice 3-speed out of a 1940 Ford pickup and am having it gone thru at the transmission shop right now. My question is what do I have to do and What else do I need to take the 4-speed out and install the 3-speed. Will it hook right up or do I need other parts???? Also does the 1940 3-speed and the 1950 4-speed take the same clutch????
Thanks For the Help!