273 to 318 engine swap info please!!

Thanks for the info, I'm having a brain fart right now. It's been a while since I've split an
engine from the tranny but I thought the pilot hole on the crank was just used on manual
transmissions. I thought the flex plate bolted to the flywheel and the torque converter bolted to the flex plate. What goes in the crankshaft pilot hole when you have an automatic??? Seems like something should go in the pilot hole to keep everything true
under torque....