Shade Baby - Pictured below are the original dimensions for GM# 370465 - Bolt -- Stud, hub (front and rear) that fit 1930-50 1/2 ton trucks. It shows the overall length of the stud listed as 1-17/32", 7/32" longer than the 1-5/16" length listed for the Filling Stations "FS-631A" Kevin mentions above.
The bigger difference though may be in the diameter and length of the knurl. The Filling station info indicates their "FS-631" is offered as a direct replacement for the original truck stud, GM# 370465. Nothing really wrong with their overall length being 3/32" shorter than original. There should still be adequate lug nut engagement when mounting your wheels.
Also, their "FS-631" knurled section shoulder length of 17/32" is 5/32" longer than their FS-631A. This comes closer to the original knurled length of 37/64". Their 17/32" knurled length is just 3/64 less than the original shoulder, but still way longer than their FS-631 shoulder that is only 3/8" (or 24/64") - 13/64" less then the stock truck stud shoulder length.
Just my thoughts, but the longer knurled shoulder length is going to fit and stay in place in your hubs better than the short one.
Hope this isn't too muddy for you and helps you decide what to get.
