Find a good running donor with the 318. Make sure it runs well. You will need lots of things to do the conversion, ie; motor,trans,rad, motor mounts or V8 K member, etc,etc. Many little items such as accelerator linkage, kickdown cable, tranny coolant lines and I'm sure others will add to the list. This is why a good donor car is usually the best bet. All there and cheaper in the long run.