With a =1 head and Indy oiling, which I assume you have it will make little difference where it is. We have run that combo a few different times with just a fitting in the cover with no issues at all.
This was a -1 headed 446 with the fitting in the top of the cover at 11" of vacuum never any oil in the tank.
"I am not ashamed to confess I am ignorant of what I do not know."