Good point. Any debris (even a strand of hair) between the bearing shell and the cap will eliminate the oil clearance, at least in one place. If the engine was running before without issues with that bearing, something to do with the assembly process has created the problem.
I recall a crankshaft-lockup problem with a Chrysler 426 Hemi we were assembling for a pull truck. Even after line boring, the thrust bearing cap would lock up the crank when it was torqued down, but substituting a lower bearing shell without the thrust flange would free it up after torquing. It turned out the car the engine came from had been in a nasty wreck, and the thrust bearing cap was bent back .010" in the middle from a hard lick on the front of the crankshaft. Another main cap (and another line bore) solved the problem.
Jerry
