They stopped using lug bolts sometime in the late 70's or early 80's.
I know with the factory alloys on my 74 Overlander the studs were barely long enough, if i remember correctly the threads actually engaged the studs only a half an inch or so, leading to several stripped hub threads which I had to helicoil. I tried finding longer bolts but to no avail. I think Uwe and others have already upgraded their axles and/or hubs so they have no problem mounting the thicker alloy wheels.
I painted my wheel bolts silver, dig around in my pics if you like.