There are four bolts holding the backing plates and steering arms to the spindles. The bottom were 7/16-20 31/4” and held in place with castle nuts and cotter pins. I need 1/2-20 31/4” (they were drilled out to 1/2” to accommodate the disc brake setup).
What are these bolts called? Do they have a specific name when drilled to accommodate a cotter pin? Can I purchase new bolts and drill to accommodate the correct dia. cotter pin, or were the originals hardened and specific grade?
