What would you do?

set the 302s aside. As much time and effort (and heart and soul) as you have poured into that car, I don't see it getting out of your hands anytime soon, so someday you might be ready to rebuild the 318 again and you can revisit potential changes. For Now, enjoy the hell out of that BEAUTIFUL car ( and pay no attention to the nitpicking of some on this thread). My stock appearing 318 in a 70 dart is always fun to drive and gets loads of attention.