The bearing clearance limits taken from various sources of engine specs give a range of .0008 to .0028 clearance.  When I take a crankshaft to be ground the standard has been .002.  Asked the shop why a more middle of the road clearance wasnt the objective and he gave me an answer, but I dont remember it. 

So why .002, and not .0017 or .0015.  Is it not important?  Would there be benefits or problems with the tighter figure? 

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.