Regarding shims, pretty much all you need to know is found in the following two references
[1] “Airframe Stress Analysis and Sizing” M.C.Y Niu 2nd ed. Section 9.11 and page 685.
[2] “Analysis and Design of Flight Vehicle Structures”, E.F.Bruhn. Section D3.5.
These include analysis...
I have hole sizes for hilok bolts from the Boeing Liaison Handbook (commercial), typical installation in Aluminium is in a transition fit hole except in fatigue critical areas such as at lower wing joints. (in 3 years of liaison engineering at Boeing I only specified a non transition fit once)...
