so I'm looking at a 1990 7.3 idi with only 152,000 miles on it. He is the third owner and the a/c still works in it the only thing wrong is it needs glow plugs. So my question is it worth buying?? He is asking 7000 and I got it down to 5000 but it's 3 hours away from where I live. So would it be worth the drive?