Hmm....things get complicated. My 7/46 Equipment Register shows IT #8000-8099 (92 cars at that date) as 38'5" (outside length) XM boxcars with "steel underframes", which presumes a wood carbody. (Otherwise the listing would show "all steel", as many IT boxcars were.) The same group shows up in my 1939 Register. So was there a second 8000-series in the 1940s, or a renumbering? In any event, none of the IT's rather large fleet of freight cars in this period shows any interchange restrictions in the ER listings.