It's called "lying". When the move was made to bearing shells with the tab at the parting line instead of the upper dowel, the shim adjustment was eliminated. Supposedly, the tolerances were tightened up enough that the shims were no longer necessary. If the oil clearance happens to be a little too tight due to an inaccurate regrinding job on the crankshaft, I have added a thin shim between the main bearing cap and the block to get things right. Just be sure the shim also overlaps the end of the bearing shell. We had to do that on one main bearing when we assembled John's 261- - - -There's a LONG story about that situation! The bearing doesn't know, nor care how it gets the proper clearance, but a too-tight bearing is a disaster waiting to happen. As always, common sense will always win over some slavish adherence to repair manual procedures.
Jerry
