Brent,
There are no Brinell hardness requirements on the drawings.
I agree that most dimensions are specified without telling the machinist how to do it. Some dimensions tell the machinist to "Grind" like the crankshaft journals, or to "Ream" and "Roll" like the cylinder bores. We now know that the cylinders should not be rolled, but instead honed like this:
https://www.hastingsmfg.com/ServiceT...efinishing.htm
Compared to a modern engine, the tolerances in a Ford Model A engine are very loose and I believe that they needed to be "broken-in" by spinning with an electric motor until the amperes (torque) dropped to a certain level.
The crankshaft connecting rod journals on drawing A-6303 are specified to be ground to 1.497 to 1.499 inch diameter (each of the rod journals could be different), and they could be ground undersize per drawing note on A-6303 which reads "see specification MS 46303 for salvaging crankshaft".
The connecting rod drawing A-6200 specifies 2 different big end diameters. A-6200-A has a big end diameter of 1.4965 to 1.4970 inches, and A-6200-B has a big end diameter that is 1.4865 to 1.4870 inches (which is .010 inches undersize).
If you were to see the big picture, every engine could have connecting rods with 4 different diameters and main bearings with 3 different diameters.
The engine assembly drawings that I have call for a pair of shims at all connecting rod and main bearings.
Regarding engine "break-in", I agree 100% with Vince Falter where he explains it here:
http://www.fordgarage.com/pages/bearingshims.htm
Once broken-in, the engine was stamped with the serial number.