You could get bearing shells that were mismatched or just plain wrong. In todays market that simply dosn't happen.
Machinists make mistakes every day and some are downright hacks so any part has potential to be out of tolerance. A micrometer will change size simply by the warmth of the hand of the person holding it and most are completly unaware this is happening. Plastigauge is a direct reading result of the actual clearance and not a calculated value base on the difference between what an I.D. and O.D. tool read. On top of that 50% of people (including machinists) use measuring tools incorrectly polluting results. When engines seize after a "professional" rebuild it is nearly always caused by incorrect use of measuring tools. When the clearance really matters all the old fart millwrights will confirm readings with plastigauge.
