Many years ago while in college I put a set of 911 wheels on my beetle. The
question came up of lug bolt/stud length. I asked one of my professors if my old
bolts would do (they were a little too short).
His answer, while slightly sexiest, has stayed in my head. His answer: You know,
Its like the buttons on a girls blouse. After the first one is undone all the
rest go much easier.

In theory any bolt only needs 1 or 2 threads to develop full strength. In
practice its best to have at 1 diameter of threads sticking out the nut.

Just something to think about for wheel conversions.