Most of the aftermarket blocks use the Cleveland (2.75) mains as well. My 445ci Windsor with the Dart block used a 4.100" Cleveland style crankshaft.
That engine was a hodge-podge....Windsor block, Cleveland mains, SBC rods....
However, I can pretty much guarantee that the ones that are saying that the regular Windsors can't go over 6000 rpm are pretty much in error.