The -4 plans, and I suppose the other models as well, say to safety wire the B-nut of the fuel tank flop tube hose fitting to the bulkhead fitting that it attaches to. It shows that the nut is drilled on one corner for safety wire. Mine isn't. I doubt I have much chance of successfully drilling into a piece of aluminum at a 60 deg angle, not to mention the risk of going through fitting and coming out in the threads on the inside. Any suggestions?