Just had a machinist in my office John, and we discussed deepening the stud holes in the wheels, and he strongly suggested against it. He said the wheels will fail in a catastrophic way, because too much "meat" will have to be taken out to deepen those holes. He has a $200,000 CNC machine that could do it easily and he would do it for free, except he won't because he feels it is truly unsafe.
Also, last night I had a former race car driver and now race team head mechanic at my place looking at the wheels. He has over a decade of racing success, and is a damn good mechanic. Anyway, he says he raced his race car for years with only 3 full turns of the lug nut, and he claims he would bet his life on it that 4.5 turns is plenty to keep the wheels securely on.
I trust him because he has no reason to lie to me; however, that is insane in my book. I am still going to go with longer studs to get the full minimum 6.5 turns davidnunn's chart shows as a requirement. I know it is more money and time, but I rather go with safe than sorry. And if I ever sell this beast, the next owner will appreciate that I did it the right way and took no shortcuts.
In the meantime, I will mount and balance the tires on these new wheels, then put them on the car temporarily to be able to take some photos to post.