Customer brought over a 6.5 NAVSTAR optimizer 2003 that was rebuilt by Milton in 2010 and had only 20 miles put on it in 12 years. 6 of the glow plugs had melted but I was successfully able to get them out without breaking them. Converted the IP from 24v to 12v and I did a 10 second dry test run on it and a compression test.

All cylinders are well above 400 psi except cylinder #2 which is at 265. I removed the head and found a long deep scratch in the cylinder wall.

I have never done a lower end before. Can I hone just the 1 cylinder and replace just the rings on one piston without affecting performance of the other cylinders?

If so, how much material can I hone off of the cylinder, what tool do I use to measure cylinder width, what specs should the rings be?

edit: pictures added