"without being abused..."
its inevitable. if you lived in japan, owned the sporty prelude, KNEW that you HAD to get a new motor before 45k wouldn't you beat the piss out of it? really its hard to find one that isn't abused. but just make sure the leak down and compression tests fall within spec. also look at the asthetics of the motor. is it covered in oil, greasy, dented, rusted, or is it clean. use good judgment.
any other questions like that look
here
v