After talking with Van's Technical Support (Joe Blank) and getting additional feedback from the Houston RV Builders forum, I ordered AN3 bolts, washers, and locknuts to replace the non-aircraft spec zinc-plated home repair versions. This change will insure that I have aircraft grade fasteners in my RV and not risk possible failure of the fastener. Using the AN3-3 bolt required that I resize drill to #12 in the elevator spar, counterbalance rib and end rib. Even with this modification, all is within clearence specification between fasteners and the edge of the material being fastened. I used Loctite thread sealent to minimize or eliminate the possibility of loosening due to vibration.
