My sister has a B7500 that somehow someway either blew a head gasket or cracked the block as there is now water in the oil. Unfortunately it was run hot and lunched the motor, her tractor has 200 hrs +/- on it.. but has been neglected and left outside over the years. ..dealer estimated 9K to fix it. .. not worth it. We found a 80hour B7500 that had been stripped of numerous parts.. but the block was still intact. Oil looked new, engine turned by hand easily and the antifreeze was still like new..so we bought it and now have started the swap over...man..is there a lot of bolts for such a small motor... the only thing I'm really concerned with is putting the injection pump apparatus back on and timing it etc.. I may just get the bu,k of the work done and bring it to the dealer to button up the loose ends and fire it up.. not sure yet.