Hey all! Im new to this forum stuff, so sorry if I do any of this wrong.
So here it is. I got a '91 7.3 IDI. I noticed a "puffing" coming from the exhaust at idle, so I did a compression test. I had 420lbs on 2 cylinders, 390lbs on 4, 360 on 1, and 200 on the last one. I understand these...