Tony, I had a couple of minutes this afternoon so I pulled a top and bottom stud off my spare axle.

Here is the skinny on the studs:
Top: 1 15/16" long, 1/2" diameter, 1/2"-13 thread on one end 3/4"of thread, 1/2"-20 thread on the other end 7/8" of thread.
Bottom: 2 1/8" long, 1/2" diameter, 1/2"-13 thread on one end 3/4" of thread, 1/2"20 thread on the other end 1" of thread.
Hope this helps,
Steve