Main Bearing Clearance

And if you are still worried, break-in the rings for a few hundred miles, and then switch over to Mobil1 or another full synthetic, and you'll never have to worry over it.

The protection of bearings with a good synthetics is unreal: I suffered an oil leak in a race (rally) and raced a turbo'd 2.6L Mitu for 2 minutes with 0 to 1/2 pressure and then the final 2 minutes at 3/4 throttle with ZERO oil pressure. (I was pissed; so it became 'finish or blow'! LOL) I pulled the motor apart afterwards and found NO scratches or wear on the bearings. No way that would have happened with straight petroleum oil; I woulda lost the whole crank trying that stunt of running with zero oil pressure! The assembled bearing clearances in that motor were around .002, and maybe .0025" on the mains. RPM's were 2500 to 6000 in racing conditions.