Rusty, I have seen plenty of cast cranks that have pilot busing from the factory, it does not make sense the factory would make two cranks for the different trans.
For the op it will be hit or miss on the engine you bought.
I have a 72 340 in my duster, cast crank, it is drilled for a pilot bushing.
I also have another 72 cast crank 340 in my building that is not drilled.
I also have a 360 cast crank that has a pilot bushing, and a mag 360 that came out of an auto, but the crank was drilled for a bushing.
And a 74 318 that is not drilled.
70 340 with the bushing, but it came out of a 4-speed car, I parted out.