When I skinned my wings, I set the spar up on 4 saw horses and shimmed it until everything was level. When I finally fitted the wings and clecoed the rear spar hole, I measured the @#$% out of them and found that they were not as much as 1/16" out anywhere. Final drill the rear spar bolt hole and move on......
Now, it's possible that I am simply an ace builder

or that the pre-punched holes would have done the job anyway...........
__________________
Paul
Mercy Air, White River FAWV
RV-10 ZU-IIZ - "Zeus"
Building Bearhawk Bravo - RV-18 not available
2019 Donation Made