Barnfind49-
Nice work! Did you sketch this up or was this your own shop build. I've found a 1955 GM shop drawing dated 4.5.55, part no. 3720900 R.P.O. 341. This is what I see in your photos. Do you have a dimension of where the triangular wheel mount plate ended up? Like you, I have a 1949 truck so distance from cab to rear wheel well won't be a problem.

Thanks for these pictures.

Todd