Thanks for the replies, divergent as they are. I asked a similar question, after later coming across a thread that's more on point (though it's similarly inconclusive) at http://www.peachparts.com/shopforum/diesel-discussion/347283-ball-bearing-vacuum-question.html#post3405098 and that's where I will probably ride this out...

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'83 300SD - daily driver
'97 Dodge Cummins
'60 & '64 Minis
...etc...