A question on installing an original '67 shoulder belt

[jabborabbo]

Here's a picture of the bolt - it's 1 1/2" long under the head with a 3/4" long shoulder, 1/2" long thread, and 1/4" long end...when I screw it into the threaded hole it bottoms out when the shoulder reaches the cab, such that the belt swings quite freely - is this normal?

Thanks!