My Uncle Tony when he was building those SCCA 302s back in the 60's-early 70s it was common practice to "make the upper rod loose" by .001 and the 427FE's if it was going to see high RPM 5500+(lol High RPM) the rods were .001 loose and for the 427s with a 428 crank he would also make the lower mains 2,3,4 loose by.001, idea there was if the crank flexed it there would still be some film.
Every Engine I have ever built has had the uppers loose by .001, some of the 6.1 hemis I've done lately have also had #2,3&4 main lower loose by .001

It's that old saying, if your engine is loose only you will know, if it's tight everyone will know.