Checking is real simple, use an old latex glove over the oil fill hole and start the engine. If the glove inflates, replace the system.

The V8 is a bear to work on, but not the PCV. It is the black round thing on the rear valve cover. Unlike most other volvos, the v8 does not have a flame trap/catch can pcv system. It's just the valve and the hose that links it to the intake.

So long as you use synthetic motor oil, you should be OK.
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Keeping it running is better than buying new