I don’t know about v8’s but for slant six motors the FSM specifies that the oil pick up is an interference fit to the oil pan floor. My assumption is that mopar v8 engines of the same era would have the same fit requirements for the oil pick up tube.
My ‘engineering’ guess for the interference requirement is so the oil pick up tube is locked in place at both ends. If the tube that is deepest in the pan was allowed to dangle, there is a good probability that at some rpm it would vibrate harmonically and that would surely crack the tube at the fixed end.