Based the compression by the amount of air movement through the engine and the force it was exploding out with.
This is my first diesel but not my first rodeo, I have rebuilt several engines, from 1 lung 2 stroke dirt bikes to big block fords. I rarely pay mechanics (except for the computer crap), but I always do plenty of research (except when I get excited and crank the engine to soon... DOH!), before tearing into a project so I'm really comfortable when I do dive in.
I appreciate the comments and suggestions regarding my tractor. After I recover from hernia surgery, I will include the top end gaskets with my injector order and pull the head, as that seems like the prudent move. The previous owner (my brother-in-law) didn't pull the injectors, his ex-girlfriends dumb assed brother did & nobody knows why, so better to spend a little extra than cause more damage.
Parts in Canada for this model seem to be hard to come by, they want $600 plus shipping for the 2 injectors (no hold downs) vs $81/ea from Hoye. Fortunately, my father lives in Wa State, so I can ship parts to him and pick them up during visits.
Question for Winston1, how do I check compression on a diesel?