Detroit Head

You should have the compact gear train with bushing type bearings on the bull gear, much tougher than the older roller bearing gear type. You also have screw in injector cups replaceable without removing the head. You will still want to reseal them while it's apart, but they're a much easier job than the older ones.

You still need to check liner protrusion, if it's not right, do not ignore it. Any problems with the cylinders can turn it into an in-frame.

Edit: I forget to mention the cylinders themselves. On the EGR engines, the cylinders do not last as long. They usually get worse toward the rear. Look for polished cylinders. That EGR soot is like a fine abrasive and wipes out the cross hatch in the cylinders. I seen some oil burners where #5 & 6 looked like a mirror.

 

B&G Machine is up there in Seattle.

I was looking at getting my cam repaired and found their website. Looks like an awesome place.

They have some vids on their website that's just pure Caterpillar porn!