Two things: 1) The original drain and level plugs are too short - only engage a few threads and thus strip those threads fairly easily. I make longer drain and level plugs that utilize all of the available threads. 2) Instead of aluminum or fiber sealing washers, use "stat-o-seal" or "dowty" type washers which required much less torque to seal properly.
Re: #1 above -
I called Charlie when I panicked after stripping the drain plug on my Eldo. A 5 minute conversation with him and a short search on the McMasters site, plus a 5-minute job after I got the new bolt/drain plug (+ 10 "extras" if I remember correctly!) & I was back in business. Phew!