one more question

Can a crank be removed from an engine without taking the heads off? I have just finished building my 318 and now it looks like I might have to take the crank back out to have the hole drilled for the pilot bushing. I haven't put the motor in the car yet, but it is completely assembled and painted. I really dont want to take it all apart, but choosing to use a 1965 crank from a 273 motor is becoming more of a headache than I thought it would be. If I could just take off the oil pan and remove the crank I would be much happier than having to completely tear apart the motor and get all new gaskets again.
Dan