Using a #30 countersink, I continued to adjust the microstop countersink until I was able to get 0.370 on the digital readout. I decided to rivet the K1100-8 platenuts to the flanges instead of creating a jig to countersink the holels for the #8 screw.
I did get a little chatter unitl the guide settled into the platenut and the results were pretty good on both flanges for the right spar. Just got one spar done tonight. Once I get the K1000-06 platnuts riveted and countersunk, I will then primer the flanges for the anondized material that was removed.