I've never done this, but one way I was told to determine if it's the valve seals that are passing oil is to pull off the rocker assembly, temporarily plug the oil passages, then put it back together and run it to see if the smoking stops. Of course you wouldn't want to run it any longer than absolutely necessary that way. I know this may sound a bit crazy, but it was a good Volvo independant mechanic that told me about doing it, so proceed as you feel comfortable doing. It might be that you could grease up the tappet/rocker arm surfaces and be OK running it like that for a several minutes.

Has anyone observed you accelerating to verify the smoke is coming from the tail pipe and not blowing out from under the car?

Good luck.
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Chris - 1990 740, 1973 1800ES (Non-running), 1993 Dodge Dakota (Still has a little paint left on it)