Questions about the Mopar Performance 340 Replacement Block P5007552AB

It doesn't sound like you have to do any machine work to use it. All the stuff they did to that block in the Hot Rod article was not necessary, really. At least that's how I understood the article. I think the only major question I have left is what is a a mid-1970s 318 left-side motor mount? Any idea where I could get one and what the part number might be?
http://www.hotrod.com/cars/project-vehicles/mopp-1010-1968-plymouth-valiant-project-70-small-block-engine-build/