[yossarian19]

Take a 1/2" ratchet, some short extensions & a set of sockets. I don't recall the socket size for the crankshaft pulley but what you want to do is turn the motor clockwise two full rotations (720 degrees) and make sure everything turns. It almost certainly will. If you pull the plugs or loosen them it will make life easier - that way you aren't fighting engine compression.

If you can get the rear tires off the ground and put the trans in Neutral, verify the driveshaft turns with no chunky / alarming noises. I'm not sure I'd bother.
At $700, it's a steal no matter what's good or bad.
Harness, ECM, accessories, brackets, rebuildable cores + selling some junk off of it = WIN