Well I offer my embarrassment because I did not read that this was an '87. I have done 616 and 617 engines which are the previous generation with an iron head.
I am not sure that the sleeve issue applies to your engine. If it does, then all that holds true.
The one useful thing I might offer on the aluminum head engine is that you don't want to mill the aluminum head, or any head on a diesel. The combustion chambers are microscopic and much loss of size will create too much compression. If you can't straighten it with about .010" or less, you will have to replace the head or have it bent in an oven.
A good friend of mine had one bent for his daughters car, and it ended up blowing the head gasket a few thousand miles later. This was such a shame because she ended up having to abandon the car.
Sorry for not reading all the post.