I would guess that NO manufacturer throws away newly machined blocks/cylinders that are slightly over listed bore size. That is why there are select-fit pistons on the engine build line. This has been going on, for some manufacturers, since the 70s that I know of. The manufacturing process has several needs, including round and straight bores, bore finish smoothness, final piston fit, and REDUCTION OF WASTE! For some, match numbers were on the blocks to tell what select piston to use during initial build. That is probably computerized for decades, now, to eliminate that extra "marking process' step.
I have seen up to 0.10 mm over advertised bore (in one or more cylinder) on a brand new production car engine. If you are measuring a bore on an engine that has never been apart, and it comes out some amount
less than 0.25mm over, it is most likely absolutely stock from the production line.
This situation is old news. Here is an interesting peek at how complicated this issue really is (try to ignore all the attitude stuff...its just the facts that are interesting):
http://www.pistonslap.com/Note: These folks writing this opinion don't understand that piston slap occurs at the ends of the stroke when the piston is basically stopped, and the crown/lands are not expanded under high thermal load, such as towing a trailer up a hill. Sometimes, you have to make a choice for piston slap, for piston survival.....like...maybe...a bike set up for turbo conversion? (hmmm....
How much over were those bores, Don?) This slap issue is always a fight between the engineering side and the Customer Satisfaction side, and seldom strictly a "cost cutting" measure, regardless what some folks might claim.
This goes a lot farther than bores and bearings. Some pushrod engines had select-fit lifters on the production line. If you took apart a brand new engine, for whatever reason, you had to make sure to get the lifters back in the correct hole. If you did it wrong you might seize a lifter, or (on hemi engines) give the customer a persistent valve noise. I know a young mechanic who got bit on that one, until the Service Manager straightened him out. It took a lot of fiddling to get that sorted out.
Complicated.