First Car Restoration by a Learning Rookie: 1968 Dodge Dart GT

Now what might be so rare/important about the 340 that I would want to replace the 225? As you know, I'm learning all about cars so hearing opinions and facts will only help bolster my knowledge!

I dont think 340s are rare or important, I'm partial to 340s because I have one. The engine is great. A 360 is a cheaper route if you wanted to build an engine and they look almost identical