if they don't know the squeeze test they wouldn't know about the infamous #14 head
http://www.peachparts.com/shopforum/showthread.php?t=103444&highlight=om603+head
better get out the flashlight, Randy, and find the serial number on the head casting! else you might not sleep well at night, OTOH, its only $600 so you can part that thing out if the heads warped and still come out way ahead.
If however you get it running right, you may just fall in love with the beast, IMHO the 603's are best diesels on the road, provided you don't have head problems.
1971 220 (gas) 4-spd manual 106441
1979 300TD w/ ’85 turbo engine 295530
1983 300D 243280
1985 300TD 217300
1987 300D 260190 #14 head and still running great!