The F-704 Bulkead needs to have one set of holes drilled to increase the hole to accomodate an AN4 bolt which will hold the F-904J Center Section Spacers in place. Initially I miss-drilled the holes, by simply enlarging the holes on the F-704A. Instead, I shlould have assembled the F-704A & B together, with the rough (PVC) spacers and temporary bolts, and drilled from the predrilled 1/4" holes into the smaller holes as a match drilling operations. As a result the free drilled holes created a small misalignment occured which precluded a smotth installation of the temporary 1/4" bolts with the spacers. As a result, Van's Technical assistance recommended assembling the bulkheads and match drilling the holes with the 1/4" drill bit and later a 1/4" reamer to allow the holes to better align. I was able to start the re-alignment procedures and got much better results match drilling from each direction (fore and aft). The holes aligned better, and the bolts slid through with less effort. So I ordered a 1/4" reamer which will hopefully further assist alignment. I was initially worried about the loss of bearing surface with the AN4 bolts, however tightness of fit (i.e. bearing surface) is not a concern as the AN4 bolt in this case is loaded in tension (as per Van's Technical Assistance) and provides additional strength to hold the F-704A & -704B together.
