Studebaker Starter Bolts
There are a few unusual fasteners used in every car. I discovered recently, in a random post on the Studebaker Drivers Club Forums, that the starter bolts on Studes are a special part rather than an off-the-shelf fastener.
The factory bolt, p/n 529367, is a special one with an unusually long collar section. The reason for this is that the long collar goes completely through the starter flange and the transmission bellhousing, keeping the two in alignment and protecting the Bendix drive gear from improperly engaging the ring gear (which could chew up both gearsets); a standard bolt's threads have a smaller diameter than the collar and allow the starter to become misaligned.
Unfortunately, dumb auto shops through the years paid no attention to this and just used whatever bolt was lying around handy.
The photo shows the difference between the special Stude bolt and a standard fastener. (The upper bolt is the Stude part.) First you spot the difference in length; the Studebaker part is a good 1/4" longer. Notice the difference in the collar length? The Stude bolt's collar is a good inch long, where the standard bolt quits at about 1/2". Finally, the Studebaker part uses fine-pitch threads, where the aftermarket bit was coarse thread.
Of course, these special bolts are long out of the parts bins. Luckily, I got a set from Rich Gahlbeck at Studebakers Northwest. Try your friendly Studebaker vendors; they'll likely be able to track you down a set, too.
Remember, the difference is in the details! Do it right and you won't have trouble.
Follow-up info, 8-2-2010:
Per a post by Rich Gahlbeck on the SDC forum, the bolts for V8 Studebaker automobiles are 1 15/16" long, with a shoulder of 1 1/8" (if you're trying to source them, this may help). Read the whole post here.