1966 k10 Shortbed Build

[66K10shortbed]

I've been working on my '66 k10 for a while now and I am hung up on a major problem. Both front axle rear shackles have sheared, and I cannot find them anywhere. I was originally going to order them from LMC but when I called them (because the part was out of stock) they told me they will no longer be selling those types of shackles. I ordered a set from Brothers and they have been on back order for almost 2 months. I got in contact with the sales manager and he said they have no idea when they will be getting them. I just wanted to know if there was anyone who knew where to find these things! Thanks everyone.