This is an amazing forum
I know the last post on this topic was from 14 years ago, but I wanted to express my amazement at how even the smallest detail can be found on the Vans Air Force forum. I am replacing the clunky old tachometer on the O-360 in my RV-6A and wondered what do with the open hole left by the removal of the tach cable. First, I found the references to Aircraft Spruce, Lycoming, and Van's parts (being the cheap ******* I am, I ordered the Van's cover). When it came in the mail yesterday, there was no place to safety wire the cap and no o-ring or gasket in the bag. Back to the forum and found this lively discussion on all the ways people have found to seal up this hole. I'm hunting for my blue Locktite thread locker right now . . .