59 AB drain tube in rear main cap

[flatford8]

A friend of mine recently bought a decent 39 coupe. The motor has been changed to the later 59 AB style.Doing the first oil change, he found a lot of sludge in the pan through the drain plug hole. He dropped the pan to clean it out. After reinstalling it, he has an oil leak. He decided to pull the motor, and clean the intake valley and timing cover to get all the sludge out of the motor and address the rear leak. When he had the pan off, I noticed the tube wasn’t in the rear main bearing cap. I mentioned it, but he got ahead of me and got the pan back on again before we did any research about the tube.
I’ve researched past threads this morning, and the only definitive answer is on a 21 stud earlier motor. so my question is, is taking the pan back off and getting a tube in that bearing cap important. I’m trying to help my friend prevent an oil leak and to end up pulling the motor again. We finally got good weather in Maine and he’d like to drive his car…….Thanks!………Mark