[71K5Randy]

Here’s a truck catalog page from ‘71. It shows 3991023 as the part for fleetside side mount carrier. Second is a GM catalog from ‘79, where Blazer’s bolt was consolidated with 3991023, because all of these bolts were different lengths but were 7/16-20 fine thread. GM notes cut to length when using these bolts. The reason I am choosing to reproduce the 6-7/8” length that matches 1rippen6’s NOS bolt is it covers everyone using both stock and bigger wheel/tire combos.