I was able to spend some time on the '87 over the weekend. I cant say I'm any closer to knowing what is wrong.

I did the diesel purge thing inserting the input and return lines into a clear bottle, it really had no effect. smoke stayed constant, returned fuel was essentially unchanged staying light green until it was almost gone. Engine noise did not get better or worse.

I read in a thread that cracking the lines open one at a time could provide some insight in narrowing which injectors are the source of the issue. Any line I cracked open made the engine lumber, from which I infer no one injector is a major contributor to the issue.

Thinking I was on the wrong track, I started looking into the turbo. I though if I lost an oil seal I could be pumping oil into the air inlet side causing the smoke, engine noise and power loss. I removed the inlet crossover to bypass the turbo to see if that made a difference. While there was some oil in the crossover, no oil was pumping out of the turbo, and having the inlet side open to fresh air made no difference. just made the sound of the air popping into the inlet louder.

Not really sure what a good next step is. Is there another test I can do to validate that its the injectors that are the root cause? If not, I figure my next step is to plan on investing in the injectors. Remove, pop test (which I do not have... ), rebuild or purchase, balance, install: feels like $300-400 hoping it fixes it. I'm ok with that, I'd just prefer to be reasonably sure I''m headed down the right path.