Hey everyone, new here. Been restoring a 65 econoline for the past few months, and right now Im swapping out the drum brakes for disc brakes. In order to fully remove the drum brakes, housing, etc, I have to pull out the rear axles, so I figure I might as well drain out the fluid while Im in there and fill it with fresh stuff. Can anyone tell me what weight oil it would take? My best guess is something like a 75w or something in that ballpark, but it would be awesome if anybody knew for sure what the correct answer was. Thanks in advance!