I just got off the phone with 4 different con-rod suppliers. ALL of them gave .940" as the width of the big end on the SBC. With stock at .945" to .948", the differences can be substantial. At this point, I guess I will have to advise using a high volume pump to anyone using these types of assemblies, which is something I heretofore stayed away from.
Stock crank, stock rods are a lot less problematic, and don't need the high-volume pump.