Datsun Roadster Forum-311s.org

Mack, the tip is probably more applicable for used (compressed) washers that you cannot find a replacement for. However, propensity for leakage will depend upon how much pressure the washer is holding back. An oil plug is not really under pressure like a brake system is. Getting everything installed, filled and pressurized only to learn of a leak is a serious PITA. For such a simple cure, its worth 2 minutes of time.

The "tube side" is to go towards the pan
The other has a thread like offset to screw it on the bolt threads they are designed to be tight then when crushed they lock on to the bolt .
The old ones are at time tough to get off
I take a chissel, plug in vise lite tap and it pulls off