Engine mounting?

Okay, I have looked around and tried to find the definitive answer to my question but do not feel confident yet in my results. I have a '73 Swinger with the original 318. I have another 318 from a '75 D100 truck that is free to me (thanks dad). It is my understanding that these two are interchangeable but I feel like I have seen some posts where they discuss different mounts. Can someone please give me a clear answer as to what I will need to make this fit, if anything at all. Thanks in advance, you guys are great.