I am doing a frame up restoration on a 52 chevy truck. This is the first restoration I have ever done. Anywhy, to my question. I want to know if I should plug the drain holes in the cowl under the door hinges? My father-in-law says to leave them be, but that does not sound right to me. Why would I want a place to let water into my hard work and let it rust it out?

Thanks,
Pat