Swappin 318's

I have a spare 318 that I want to put in my Dart. I picked it up over the summer and is sitting on my stand. I was told it has about 75 to 80k miles on it. I want to make sure that its it decent shape before I put it in.

What should I do to make sure it's in good working order? Anything thing I should look for? Should get a gasket kit and replace all the gaskets before putting it in? Do a leak down test? It seems to spin OK.