7.3 powerstroke

Engine was pulled out of a 96 f350 with 157,000 miles on it. Was a very strong running motor until it suddenly had a lot of blowby on the interstate one day. Pulled over and had tbe truck towed. My mechanic thought maybe an injector broke and washed a single cylinder. So I just had him swap motors with a different used one instead of rebuilding this one. Never leaked a drop of oil before, ran strong.