318 swap

Hi everyone,
I have a 225 /6 in my 74 duster, and I was given a 318 by my uncle and he said it would marry up to the slant 6 tranny, and if not pushed hard it should be fine.

What do you guys think, I'm leaning towards looking for a tranny that is a for a 318. and also what about the rear end does it need to be changed as well.

Thanks for the advance for the advice