Front suspension part question

[Railroadman]

I have ordered the shop manual and supplement but don't have them yet. So I'll ask the question here so I can continue with the reassembly.

1966 C20, I have the part below. Two, one for each side. My pics during teardown show it was not above (inside) the frame rail. They either go under the crossmember as reinforcement for the 3 bolts extending up through the frame, OR they go between the crossmember and the frame as a spacer. I'm guessing under the crossmember? Thanks!