My on center doesn't , there,s no pick up. My off center does. The way the pick up is designed it gets hung up on the wind age tray. It's a custom rectangular piece. 2 inches is more than enough. Actually I wanted to cut out the center of the cross member and add a tubular pipe to make it even easier.
It will depend on whether or not your block uses an internal pickup. Early On center blocks had the provision for a pick up but when they changed the design to a cross bolted the #1 main cap that went away. If the car has a cross bolted block there should be adequate clearance to remove the pan. Worst case scenario you might have to jack the motor up slightly.