New guy with some basic Dart questions!

So is going from a 340 to a 383 or 400 just a matter of changing the mounting blocks or is it more detailed than that? (assuming I'm starting with a roller)
If you already have the V-8 K member then Shumacher mounts will make it slick and easy. Even if you don't, the 6 cylinder frame doesn't take all that much modification...
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