Spigot bush
This is a photo of a Blue 202 crank with a manual spigot bush fitted. Manual trans use a brass bush that fits flush with the crank like in the photo and the auto bush is made of steel and has a tapered bit that sticks out a bit for the torque converter to centre on. The V8 should have the same size hole in the middle as the 6 but the outer diameter is a bit bigger. The spigot bush is the bit in the centre of the crankshaft. You can tap a new bush in with a hammer, but be carefull because the brass bush can be easily dented or chipped. Its best to use a bit of wood as a punch that you hit with a hammer to hit the bush in