A "Chevy 350"? Oh, all 5.7L V8s from GM must be the same. LS1, LT1, or and L98. Yet, I doubt you were even referring to one of those. I bet you mean one of the 1st gen SBC 5.7Ls.
No offense, but only someone who does not know what they are talking about says they want to put a "Chevy 350" into a car. I suggest becoming educated on the matter and then make a choice as the which specific engine you want. Especially before deciding to put it in a car it never came in.
As far as "swapping" a motor goes it is simple. Make the engine physically fit and then fab up some mounts. Cut and re-weld parts of the unibody, whatever it is cake work. As far as headers and wires, etc. Those can be made/modified to fit. So basically, decide what motor you want based on the motor's performance, don't be worried it won't fit.