This was a 1988 GTU 13B that was well taken care of, sat for awhile and now compression / power loss have taken over.
We see this on older motors, what do we do about it? I happened to have a solid spare rear housing to replace it with. If reused, it would have soon been eating coolant and pushing towards an early death. Not acceptable.
Can you fix these issues, is there a process that is proven? Everyone will have their opinion, my experience is that it is important to do it right, that means replacing it. Yes, that does take time, however as I tell my customers, I do not want to see the inside of this motor for a long time. Racing or street performance, it doesn't matter.