Thanks for the replies guys! I went and looked at it again today, but didn't get to drive it because it was raining. Its at a classic car dealership(it's on a guys farm) an hour south of Springfield, IL. It's a '72 240 and looks to be in amazing condition. They are asking $8,450 for it. I think the odometer said 66,XXX or 86,XXX; couldn't tell because the needle was covering the first number. But I know they will deal on it because he said it's been there for 6 months and it needs to go. It had trouble starting up, but if I got it I would redo the engine or find another engine to put in it. I have to decide whether or not I could afford this because I'm only 18 and I'm in college. I didn't see any rust, although I didn't get the best look at the underbody. But the previous owner left EVERYTHING with the car. He has before, during, and after pictures of the restoration. He repaired the rust and even welded in some metal to replace the rusted parts. Here are a few pictures I took.
Out of curiousity, has anyone on here dropped another engine in a Z? Possibly a Skyline motor or even a small block v-8.