I looked at the ends and also the height. The SP&S car is taller than the SP car which has a 10'-0" IH, and the GN-built cars for the SP&S had the 10'-0" IH also (13000 series, 12 panel sides, etc.).
Andy -
Do you have numbers fro the SP&S 11000 series cars with the older doors? That might tell a story.
