[Ironhorse]

Trying to determine if my '71 K10 1/2 ton with the original blue plastic twist lock hubs needs or should have a flat washer or lock washer under the 6 chrome trim ring socket head screws. Right now it has a miss match batch of rusty socket head 10-24 NF shouldered screws on one side and common slot or straight headed 10-24 NF shouldered screws on the other side. Pretty sure the socket head screws are correct but not sure about the flat washers or lock washers beneath the screw head? Currently none at all. Looked in my assembly manual and the service manual but can't seem to find the correct parts break down pic. Anyone know what is correct and original from the General? Thanks in advance,