FWIW, I'm thinking the majority of factory cranks only had a center drilled for machining. Others had various rough dimensions drilled. Then there are the application specific for the manual trans. Those LA & B-RB cranks that are not drilled can house the newer converter snout bearing for a shortened input shaft. It tends to be easier to install a bearing and cut an input rather than drilling a crank to size, pressing, then sizing the bushing, especially with the crank in the engine and the engine in the car.
