I am looking to find out what the height of the truss rod support were on these cars. the drawings that I have access to are a little vague on this (Maxwell) and Derrell has yet to offer his fine drawings on CD yet.
According to Derrell Poole's drawings for the phase 2 (1908) boxcars:
The queen posts were 6" from bottom of needle beam to top of the crotch of the web (top of truss rod). The needle beams were 4" x 10", notched for the side sills so 7 1/2" protruded from bottom of side sill/sheathing.
Total distance from bottom of side sill / sheathing to top of truss rod was 13 1/2". The truss rods were 1 1/8" in diameter.