looking for info on magnum small block

Well this is my engine question so please be easy on me. well i planed on installing a 440 etc into my 73 dart. but it is hard when you have little to no money lol. allso i gave the 318 engine out of my 73 dart to my son for his birth day. allso my car came with a 12.5.1 340 short block that only needs a set of heads to make it run. But i would really like to keep my car streetable. so i was thinking about trying to sell my 340 short block and buy me a 360 magnum motor out of a truck,van etc. so with that is there a one year magnum motor better than the rest? or they all pretty much the same. I know i will have to change the truck pan to a car pan and the front cover. allso i will get a new intake for it allso. but is there anything elese i am forgetting?? sorry for all the questions i have just been a big block guy. here is a pick of my car. thanks Mopar658)