With the compression you have (like new, for all intents and purposes, 300 is the wear limit), your valves and rings are fine.

Oil burning is almost certainly valve stems/valve stem seals or vac pump, most likely vac pump.

Heavy smoke at full throttle, with injection timing correct, is either a stuck injection timer or stretched timing chain.

I'd check the chain -- if worn, replace, then reset injection timing. Black smoke should go away. If not (and you may want to check anyway), reduce the max fuel delivery on the pump. Lots of people try to get more power by turning up the max fuel delivery, getting instead more smoke a full throttle. Also known as the altitude adjuster.... or ALDA.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!